21356052 has 24 divisors (see below), whose sum is σ = 51998016. Its totient is φ = 6809088.

The previous prime is 21356051. The next prime is 21356089. The reversal of 21356052 is 25065312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38413 + ... + 38964.

It is an arithmetic number, because the mean of its divisors is an integer number (2166584).

Almost surely, 2^21356052 is an apocalyptic number.

It is an amenable number.

21356052 is an abundant number, since it is smaller than the sum of its proper divisors (30641964).

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

21356052 is a wasteful number, since it uses less digits than its factorization.

21356052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77407 (or 77405 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 21356052 is about 4621.2608669063. The cubic root of 21356052 is about 277.4429263356.

It can be divided in two parts, 213 and 56052, that added together give a palindrome (56265).

The spelling of 21356052 in words is "twenty-one million, three hundred fifty-six thousand, fifty-two".