21037420 has 24 divisors (see below), whose sum is σ = 44279424. Its totient is φ = 8395776.

The previous prime is 21037411. The next prime is 21037439. The reversal of 21037420 is 2473012.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10629 + ... + 12451.

It is an arithmetic number, because the mean of its divisors is an integer number (1844976).

Almost surely, 2^21037420 is an apocalyptic number.

21037420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21037420 is an abundant number, since it is smaller than the sum of its proper divisors (23242004).

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

21037420 is a wasteful number, since it uses less digits than its factorization.

21037420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409 (or 2407 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21037420 is about 4586.6567344854. The cubic root of 21037420 is about 276.0561917376.

The spelling of 21037420 in words is "twenty-one million, thirty-seven thousand, four hundred twenty".