21229156 has 24 divisors (see below), whose sum is σ = 42116480. Its totient is φ = 9281952.

The previous prime is 21229147. The next prime is 21229163. The reversal of 21229156 is 65192212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9756 + ... + 11731.

Almost surely, 2^21229156 is an apocalyptic number.

21229156 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21229156 is a deficient number, since it is larger than the sum of its proper divisors (20887324).

21229156 is a wasteful number, since it uses less digits than its factorization.

21229156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21523 (or 21521 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 21229156 is about 4607.5108247296. The cubic root of 21229156 is about 276.8923195738.

The spelling of 21229156 in words is "twenty-one million, two hundred twenty-nine thousand, one hundred fifty-six".