21971008 has 28 divisors (see below), whose sum is σ = 43832272. Its totient is φ = 10926720.

The previous prime is 21970981. The next prime is 21971017. The reversal of 21971008 is 80017912.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12691 + ... + 14317.

Almost surely, 2^21971008 is an apocalyptic number.

It is an amenable number.

21971008 is a deficient number, since it is larger than the sum of its proper divisors (21861264).

21971008 is a wasteful number, since it uses less digits than its factorization.

21971008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1850 (or 1840 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 21971008 is about 4687.3241833694. The cubic root of 21971008 is about 280.0807930117.

The spelling of 21971008 in words is "twenty-one million, nine hundred seventy-one thousand, eight".