21499290 has 32 divisors (see below), whose sum is σ = 57332160. Its totient is φ = 5733072.

The previous prime is 21499277. The next prime is 21499307. The reversal of 21499290 is 9299412.

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, 39544 + ... + 40083.

It is an arithmetic number, because the mean of its divisors is an integer number (1791630).

Almost surely, 2^21499290 is an apocalyptic number.

21499290 is an abundant number, since it is smaller than the sum of its proper divisors (35832870).

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

21499290 is a wasteful number, since it uses less digits than its factorization.

21499290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79643 (or 79637 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 21499290 is about 4636.7326858468. The cubic root of 21499290 is about 278.0618274231.

The spelling of 21499290 in words is "twenty-one million, four hundred ninety-nine thousand, two hundred ninety".