21919908 has 12 divisors (see below), whose sum is σ = 51146480. Its totient is φ = 7306632.

The previous prime is 21919903. The next prime is 21919927. The reversal of 21919908 is 80991912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21919903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 913318 + ... + 913341.

Almost surely, 2^21919908 is an apocalyptic number.

It is an amenable number.

21919908 is an abundant number, since it is smaller than the sum of its proper divisors (29226572).

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

21919908 is a wasteful number, since it uses less digits than its factorization.

21919908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826666 (or 1826664 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 21919908 is about 4681.8701391645. The cubic root of 21919908 is about 279.8634878770.

The spelling of 21919908 in words is "twenty-one million, nine hundred nineteen thousand, nine hundred eight".