20518938 has 36 divisors (see below), whose sum is σ = 48871914. Its totient is φ = 6217200.

The previous prime is 20518909. The next prime is 20518943. The reversal of 20518938 is 83981502.

It can be written as a sum of positive squares in only one way, i.e., 18688329 + 1830609 = 4323^2 + 1353^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2533 + ... + 6888.

Almost surely, 2^20518938 is an apocalyptic number.

20518938 is an abundant number, since it is smaller than the sum of its proper divisors (28352976).

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

20518938 is a wasteful number, since it uses less digits than its factorization.

20518938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9451 (or 9437 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 20518938 is about 4529.7834385321. The cubic root of 20518938 is about 273.7694350373.

The spelling of 20518938 in words is "twenty million, five hundred eighteen thousand, nine hundred thirty-eight".