20788904138 has 16 divisors (see below), whose sum is σ = 33910042824. Its totient is φ = 9518607360.

The previous prime is 20788904111. The next prime is 20788904153. The reversal of 20788904138 is 83140988702.

It can be written as a sum of positive squares in 4 ways, for example, as 20436703849 + 352200289 = 142957^2 + 18767^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8261423 + ... + 8263938.

Almost surely, 2^20788904138 is an apocalyptic number.

20788904138 is a deficient number, since it is larger than the sum of its proper divisors (13121138686).

20788904138 is a wasteful number, since it uses less digits than its factorization.

20788904138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16525417.

The product of its (nonzero) digits is 774144, while the sum is 50.

The spelling of 20788904138 in words is "twenty billion, seven hundred eighty-eight million, nine hundred four thousand, one hundred thirty-eight".