21037534 has 32 divisors (see below), whose sum is σ = 39234240. Its totient is φ = 8252928.

The previous prime is 21037487. The next prime is 21037537. The reversal of 21037534 is 43573012.

It is a junction number, because it is equal to n+sod(n) for n = 21037499 and 21037508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21037537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7612 + ... + 10000.

It is an arithmetic number, because the mean of its divisors is an integer number (1226070).

Almost surely, 2^21037534 is an apocalyptic number.

21037534 is a deficient number, since it is larger than the sum of its proper divisors (18196706).

21037534 is a wasteful number, since it uses less digits than its factorization.

21037534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2452.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21037534 is about 4586.6691618210. The cubic root of 21037534 is about 276.0566903784.

The spelling of 21037534 in words is "twenty-one million, thirty-seven thousand, five hundred thirty-four".