21302790 has 32 divisors (see below), whose sum is σ = 51425280. Its totient is φ = 5647584.

The previous prime is 21302789. The next prime is 21302833. The reversal of 21302790 is 9720312.

It is a self number, because there is not a number n which added to its sum of digits gives 21302790.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3387 + ... + 7353.

It is an arithmetic number, because the mean of its divisors is an integer number (1607040).

Almost surely, 2^21302790 is an apocalyptic number.

21302790 is an abundant number, since it is smaller than the sum of its proper divisors (30122490).

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

21302790 is a wasteful number, since it uses less digits than its factorization.

21302790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4156.

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

The square root of 21302790 is about 4615.4945563829. The cubic root of 21302790 is about 277.2120867444.

The spelling of 21302790 in words is "twenty-one million, three hundred two thousand, seven hundred ninety".