20997528 has 32 divisors (see below), whose sum is σ = 54777600. Its totient is φ = 6694688.

The previous prime is 20997523. The next prime is 20997539. The reversal of 20997528 is 82579902.

It is a super-2 number, since 2×20997528² = 881792364221568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20997528.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20997521) 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, 18468 + ... + 19571.

It is an arithmetic number, because the mean of its divisors is an integer number (1711800).

Almost surely, 2^20997528 is an apocalyptic number.

It is an amenable number.

20997528 is an abundant number, since it is smaller than the sum of its proper divisors (33780072).

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

20997528 is a wasteful number, since it uses less digits than its factorization.

20997528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38071 (or 38067 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 20997528 is about 4582.3059697056. The cubic root of 20997528 is about 275.8815917204.

The spelling of 20997528 in words is "twenty million, nine hundred ninety-seven thousand, five hundred twenty-eight".