21916908 has 36 divisors (see below), whose sum is σ = 59663968. Its totient is φ = 6743520.

The previous prime is 21916901. The next prime is 21916967. The reversal of 21916908 is 80961912.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21916901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22948 + ... + 23883.

Almost surely, 2^21916908 is an apocalyptic number.

It is an amenable number.

21916908 is an abundant number, since it is smaller than the sum of its proper divisors (37747060).

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

21916908 is a wasteful number, since it uses less digits than its factorization.

21916908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46854 (or 46849 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 21916908 is about 4681.5497434076. The cubic root of 21916908 is about 279.8507197460.

The spelling of 21916908 in words is "twenty-one million, nine hundred sixteen thousand, nine hundred eight".