21032790 has 32 divisors (see below), whose sum is σ = 50823936. Its totient is φ = 5570400.

The previous prime is 21032789. The next prime is 21032807. The reversal of 21032790 is 9723012.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21032790.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2209 + ... + 6851.

It is an arithmetic number, because the mean of its divisors is an integer number (1588248).

Almost surely, 2^21032790 is an apocalyptic number.

21032790 is an abundant number, since it is smaller than the sum of its proper divisors (29791146).

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

21032790 is a wasteful number, since it uses less digits than its factorization.

21032790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4804.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 21032790 is about 4586.1519817817. The cubic root of 21032790 is about 276.0359383994.

The spelling of 21032790 in words is "twenty-one million, thirty-two thousand, seven hundred ninety".