20447940138 has 8 divisors (see below), whose sum is σ = 40895880288. Its totient is φ = 6815980044.

The previous prime is 20447940091. The next prime is 20447940157. The reversal of 20447940138 is 83104974402.

It is a sphenic number, since it is the product of 3 distinct primes.

20447940138 is an admirable number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 20447940138.

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, 1703995006 + ... + 1703995017.

It is an arithmetic number, because the mean of its divisors is an integer number (5111985036).

Almost surely, 2^20447940138 is an apocalyptic number.

20447940138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20447940138 is a wasteful number, since it uses less digits than its factorization.

20447940138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3407990028.

The product of its (nonzero) digits is 193536, while the sum is 42.

The spelling of 20447940138 in words is "twenty billion, four hundred forty-seven million, nine hundred forty thousand, one hundred thirty-eight".