20318731877 has 2 divisors, whose sum is σ = 20318731878. Its totient is φ = 20318731876.

The previous prime is 20318731871. The next prime is 20318731903. The reversal of 20318731877 is 77813781302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20232502081 + 86229796 = 142241^2 + 9286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20318731877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20318731871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10159365938 + 10159365939.

It is an arithmetic number, because the mean of its divisors is an integer number (10159365939).

Almost surely, 2^20318731877 is an apocalyptic number.

It is an amenable number.

20318731877 is a deficient number, since it is larger than the sum of its proper divisors (1).

20318731877 is an equidigital number, since it uses as much as digits as its factorization.

20318731877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 395136, while the sum is 47.

The spelling of 20318731877 in words is "twenty billion, three hundred eighteen million, seven hundred thirty-one thousand, eight hundred seventy-seven".