20978008 has 16 divisors (see below), whose sum is σ = 39600000. Its totient is φ = 10418016.

The previous prime is 20977967. The next prime is 20978011. The reversal of 20978008 is 80087902.

It is a happy number.

It is a congruent number.

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, 7608 + ... + 9991.

It is an arithmetic number, because the mean of its divisors is an integer number (2475000).

Almost surely, 2^20978008 is an apocalyptic number.

It is an amenable number.

20978008 is a deficient number, since it is larger than the sum of its proper divisors (18621992).

20978008 is a wasteful number, since it uses less digits than its factorization.

20978008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17754 (or 17750 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 20978008 is about 4580.1755424874. The cubic root of 20978008 is about 275.7960756493.

The spelling of 20978008 in words is "twenty million, nine hundred seventy-eight thousand, eight".