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BaseRepresentation
bin10011000100
31200012
4103010
514340
65352
73362
oct2304
91605
101220
11a0a
12858
1372b
14632
15565
hex4c4

1220 has 12 divisors (see below), whose sum is σ = 2604. Its totient is φ = 480.

The previous prime is 1217. The next prime is 1223. The reversal of 1220 is 221.

1220 is nontrivially palindromic in base 11, base 12, base 15 and base 16.

1220 is an esthetic number in base 15, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (1217) and next prime (1223).

It can be written as a sum of positive squares in 2 ways, for example, as 196 + 1024 = 14^2 + 32^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

1220 is an undulating number in base 11, base 12, base 15 and base 16.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (1223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11 + ... + 50.

It is an arithmetic number, because the mean of its divisors is an integer number (217).

1220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220 is an abundant number, since it is smaller than the sum of its proper divisors (1384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1302).

1220 is a wasteful number, since it uses less digits than its factorization.

1220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 1220 is about 34.9284983931. The cubic root of 1220 is about 10.6852973015.

Adding to 1220 its reverse (221), we get a palindrome (1441).

Subtracting from 1220 its reverse (221), we obtain a palindrome (999).

It can be divided in two parts, 12 and 20, that added together give a 5-th power (32 = 25).

The spelling of 1220 in words is "one thousand, two hundred twenty", and thus it is an iban number.

Divisors: 1 2 4 5 10 20 61 122 244 305 610 1220