21037620 has 48 divisors (see below), whose sum is σ = 59105088. Its totient is φ = 5591040.

The previous prime is 21037609. The next prime is 21037631. The reversal of 21037620 is 2673012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21037609) and next prime (21037631).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32500 + ... + 33140.

It is an arithmetic number, because the mean of its divisors is an integer number (1231356).

Almost surely, 2^21037620 is an apocalyptic number.

21037620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21037620 is an abundant number, since it is smaller than the sum of its proper divisors (38067468).

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

21037620 is a wasteful number, since it uses less digits than its factorization.

21037620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200 (or 1198 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21037620 is about 4586.6785368063. The cubic root of 21037620 is about 276.0570665448.

The spelling of 21037620 in words is "twenty-one million, thirty-seven thousand, six hundred twenty".