21037530 has 32 divisors (see below), whose sum is σ = 52121088. Its totient is φ = 5428800.

The previous prime is 21037487. The next prime is 21037537. The reversal of 21037530 is 3573012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21037497 and 21037506.

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, 10381 + ... + 12240.

It is an arithmetic number, because the mean of its divisors is an integer number (1628784).

Almost surely, 2^21037530 is an apocalyptic number.

21037530 is an abundant number, since it is smaller than the sum of its proper divisors (31083558).

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

21037530 is a wasteful number, since it uses less digits than its factorization.

21037530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22662.

The product of its (nonzero) digits is 630, while the sum is 21.

The square root of 21037530 is about 4586.6687257747. The cubic root of 21037530 is about 276.0566728822.

The spelling of 21037530 in words is "twenty-one million, thirty-seven thousand, five hundred thirty".