21764108 has 24 divisors (see below), whose sum is σ = 39588864. Its totient is φ = 10458000.

The previous prime is 21764089. The next prime is 21764111. The reversal of 21764108 is 80146712.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20183 + ... + 21233.

It is an arithmetic number, because the mean of its divisors is an integer number (1649536).

Almost surely, 2^21764108 is an apocalyptic number.

It is an amenable number.

21764108 is a deficient number, since it is larger than the sum of its proper divisors (17824756).

21764108 is a wasteful number, since it uses less digits than its factorization.

21764108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253 (or 1251 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21764108 is about 4665.2018177138. The cubic root of 21764108 is about 279.1988493479.

The spelling of 21764108 in words is "twenty-one million, seven hundred sixty-four thousand, one hundred eight".