21156652 has 24 divisors (see below), whose sum is σ = 42517440. Its totient is φ = 9110160.

The previous prime is 21156647. The next prime is 21156661. The reversal of 21156652 is 25665112.

It is a self number, because there is not a number n which added to its sum of digits gives 21156652.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11818 + ... + 13489.

It is an arithmetic number, because the mean of its divisors is an integer number (1771560).

Almost surely, 2^21156652 is an apocalyptic number.

21156652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21156652 is an abundant number, since it is smaller than the sum of its proper divisors (21360788).

21156652 is a wasteful number, since it uses less digits than its factorization.

21156652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25341 (or 25339 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 21156652 is about 4599.6360725605. The cubic root of 21156652 is about 276.5767363074.

The spelling of 21156652 in words is "twenty-one million, one hundred fifty-six thousand, six hundred fifty-two".