20347665138 has 12 divisors (see below), whose sum is σ = 44086607838. Its totient is φ = 6782555040.

The previous prime is 20347665137. The next prime is 20347665161. The reversal of 20347665138 is 83156674302.

It can be written as a sum of positive squares in only one way, i.e., 20025929169 + 321735969 = 141513^2 + 17937^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20347665093 and 20347665102.

It is not an unprimeable number, because it can be changed into a prime (20347665133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 565212903 + ... + 565212938.

Almost surely, 2^20347665138 is an apocalyptic number.

20347665138 is an abundant number, since it is smaller than the sum of its proper divisors (23738942700).

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

20347665138 is a wasteful number, since it uses less digits than its factorization.

20347665138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130425849 (or 1130425846 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 20347665138 in words is "twenty billion, three hundred forty-seven million, six hundred sixty-five thousand, one hundred thirty-eight".