1211220 has 48 divisors (see below), whose sum is σ = 3769920. Its totient is φ = 322848.

The previous prime is 1211207. The next prime is 1211227. The reversal of 1211220 is 221121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 582 + ... + 1661.

It is an arithmetic number, because the mean of its divisors is an integer number (78540).

2^1211220 is an apocalyptic number.

1211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211220 is an abundant number, since it is smaller than the sum of its proper divisors (2558700).

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

1211220 is a wasteful number, since it uses less digits than its factorization.

1211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261 (or 2253 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1211220 is about 1100.5544057429. The cubic root of 1211220 is about 106.5960252758.

Adding to 1211220 its reverse (221121), we get a palindrome (1432341).

Subtracting from 1211220 its reverse (221121), we obtain a palindrome (990099).

It can be divided in two parts, 1211 and 220, that added together give a triangular number (1431 = T₅₃).

The spelling of 1211220 in words is "one million, two hundred eleven thousand, two hundred twenty".