20101808 has 20 divisors (see below), whose sum is σ = 39898488. Its totient is φ = 9805440.

The previous prime is 20101771. The next prime is 20101817. The reversal of 20101808 is 80810102.

It is a self number, because there is not a number n which added to its sum of digits gives 20101808.

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, 14666 + ... + 15977.

Almost surely, 2^20101808 is an apocalyptic number.

It is an amenable number.

20101808 is a deficient number, since it is larger than the sum of its proper divisors (19796680).

20101808 is a wasteful number, since it uses less digits than its factorization.

20101808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30692 (or 30686 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 20101808 is about 4483.5039868389. The cubic root of 20101808 is about 271.9015647271.

The spelling of 20101808 in words is "twenty million, one hundred one thousand, eight hundred eight".