21037580 has 12 divisors (see below), whose sum is σ = 44178960. Its totient is φ = 8415024.

The previous prime is 21037567. The next prime is 21037589. The reversal of 21037580 is 8573012.

It is not an unprimeable number, because it can be changed into a prime (21037589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525920 + ... + 525959.

It is an arithmetic number, because the mean of its divisors is an integer number (3681580).

Almost surely, 2^21037580 is an apocalyptic number.

21037580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21037580 is an abundant number, since it is smaller than the sum of its proper divisors (23141380).

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

21037580 is a wasteful number, since it uses less digits than its factorization.

21037580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051888 (or 1051886 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 21037580 is about 4586.6741763504. The cubic root of 21037580 is about 276.0568915838.

The spelling of 21037580 in words is "twenty-one million, thirty-seven thousand, five hundred eighty".