21499516 has 12 divisors (see below), whose sum is σ = 38641288. Its totient is φ = 10459152.

The previous prime is 21499501. The next prime is 21499561. The reversal of 21499516 is 61599412.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72486 + ... + 72781.

Almost surely, 2^21499516 is an apocalyptic number.

It is an amenable number.

21499516 is a deficient number, since it is larger than the sum of its proper divisors (17141772).

21499516 is a wasteful number, since it uses less digits than its factorization.

21499516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145308 (or 145306 counting only the distinct ones).

The product of its digits is 19440, while the sum is 37.

The square root of 21499516 is about 4636.7570563919. The cubic root of 21499516 is about 278.0628017460.

The spelling of 21499516 in words is "twenty-one million, four hundred ninety-nine thousand, five hundred sixteen".