1281220 has 36 divisors (see below), whose sum is σ = 2843820. Its totient is φ = 484288.

The previous prime is 1281211. The next prime is 1281221. The reversal of 1281220 is 221821.

It can be written as a sum of positive squares in 2 ways, for example, as 565504 + 715716 = 752^2 + 846^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1281194 and 1281203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27237 + ... + 27283.

It is an arithmetic number, because the mean of its divisors is an integer number (78995).

2^1281220 is an apocalyptic number.

1281220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1281220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1421910).

1281220 is an abundant number, since it is smaller than the sum of its proper divisors (1562600).

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

1281220 is a wasteful number, since it uses less digits than its factorization.

1281220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 1281220 is about 1131.9098904065. The cubic root of 1281220 is about 108.6111894339.

The spelling of 1281220 in words is "one million, two hundred eighty-one thousand, two hundred twenty".