21064290 has 32 divisors (see below), whose sum is σ = 54444096. Its totient is φ = 5184960.

The previous prime is 21064273. The next prime is 21064291. The reversal of 21064290 is 9246012.

It is a self number, because there is not a number n which added to its sum of digits gives 21064290.

It is not an unprimeable number, because it can be changed into a prime (21064291) 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, 26616 + ... + 27395.

It is an arithmetic number, because the mean of its divisors is an integer number (1701378).

Almost surely, 2^21064290 is an apocalyptic number.

21064290 is an abundant number, since it is smaller than the sum of its proper divisors (33379806).

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

21064290 is a wasteful number, since it uses less digits than its factorization.

21064290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54034.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21064290 is about 4589.5849485547. The cubic root of 21064290 is about 276.1736724626.

The spelling of 21064290 in words is "twenty-one million, sixty-four thousand, two hundred ninety".