21037518 has 12 divisors (see below), whose sum is σ = 45581328. Its totient is φ = 7012500.

The previous prime is 21037487. The next prime is 21037537. The reversal of 21037518 is 81573012.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21037491 and 21037500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 584358 + ... + 584393.

It is an arithmetic number, because the mean of its divisors is an integer number (3798444).

Almost surely, 2^21037518 is an apocalyptic number.

21037518 is an abundant number, since it is smaller than the sum of its proper divisors (24543810).

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

21037518 is a wasteful number, since it uses less digits than its factorization.

21037518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1168759 (or 1168756 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 21037518 is about 4586.6674176356. The cubic root of 21037518 is about 276.0566203938.

It can be divided in two parts, 2 and 1037518, that added together give a triangular number (1037520 = T₁₄₄₀).

The spelling of 21037518 in words is "twenty-one million, thirty-seven thousand, five hundred eighteen".