21037020 has 24 divisors (see below), whose sum is σ = 58903824. Its totient is φ = 5609856.

The previous prime is 21037013. The next prime is 21037021. The reversal of 21037020 is 2073012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21037021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175249 + ... + 175368.

It is an arithmetic number, because the mean of its divisors is an integer number (2454326).

Almost surely, 2^21037020 is an apocalyptic number.

21037020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21037020 is an abundant number, since it is smaller than the sum of its proper divisors (37866804).

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

21037020 is a wasteful number, since it uses less digits than its factorization.

21037020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350629 (or 350627 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 21037020 is about 4586.6131295325. The cubic root of 21037020 is about 276.0544421064.

The spelling of 21037020 in words is "twenty-one million, thirty-seven thousand, twenty".