12156220 has 24 divisors (see below), whose sum is σ = 26409600. Its totient is φ = 4694592.

The previous prime is 12156217. The next prime is 12156233. The reversal of 12156220 is 2265121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9900 + ... + 11059.

It is an arithmetic number, because the mean of its divisors is an integer number (1100400).

Almost surely, 2^12156220 is an apocalyptic number.

12156220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12156220 is an abundant number, since it is smaller than the sum of its proper divisors (14253380).

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

12156220 is a wasteful number, since it uses less digits than its factorization.

12156220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20997 (or 20995 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 12156220 is about 3486.5771180342. The cubic root of 12156220 is about 229.9320530229.

The spelling of 12156220 in words is "twelve million, one hundred fifty-six thousand, two hundred twenty".