20990008 has 16 divisors (see below), whose sum is σ = 42383880. Its totient is φ = 9687648.

The previous prime is 20989987. The next prime is 20990023. The reversal of 20990008 is 80009902.

It is a happy number.

It is a super-4 number, since 4×20990008⁴ (a number of 30 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100810 + ... + 101017.

Almost surely, 2^20990008 is an apocalyptic number.

It is an amenable number.

20990008 is an abundant number, since it is smaller than the sum of its proper divisors (21393872).

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

20990008 is a wasteful number, since it uses less digits than its factorization.

20990008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201846 (or 201842 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 20990008 is about 4581.4853486615. The cubic root of 20990008 is about 275.8486532829.

The spelling of 20990008 in words is "twenty million, nine hundred ninety thousand, eight".