18576638636681 has 2 divisors, whose sum is σ = 18576638636682. Its totient is φ = 18576638636680.

The previous prime is 18576638636671. The next prime is 18576638636693. The reversal of 18576638636681 is 18663683667581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18574238126656 + 2400510025 = 4309784^2 + 48995^2 .

It is a cyclic number.

It is not a de Polignac number, because 18576638636681 - 2³⁰ = 18575564894857 is a prime.

It is a super-2 number, since 2×18576638636681² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18576638636599 and 18576638636608.

It is not a weakly prime, because it can be changed into another prime (18576638636671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9288319318340 + 9288319318341.

It is an arithmetic number, because the mean of its divisors is an integer number (9288319318341).

Almost surely, 2^{18576638636681} is an apocalyptic number.

It is an amenable number.

18576638636681 is a deficient number, since it is larger than the sum of its proper divisors (1).

18576638636681 is an equidigital number, since it uses as much as digits as its factorization.

18576638636681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1254113280, while the sum is 74.

The spelling of 18576638636681 in words is "eighteen trillion, five hundred seventy-six billion, six hundred thirty-eight million, six hundred thirty-six thousand, six hundred eighty-one".