18972977354657 has 2 divisors, whose sum is σ = 18972977354658. Its totient is φ = 18972977354656.

The previous prime is 18972977354627. The next prime is 18972977354663. The reversal of 18972977354657 is 75645377927981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14907931044241 + 4065046310416 = 3861079^2 + 2016196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18972977354657 is a prime.

It is not a weakly prime, because it can be changed into another prime (18972977354627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9486488677328 + 9486488677329.

It is an arithmetic number, because the mean of its divisors is an integer number (9486488677329).

Almost surely, 2^{18972977354657} is an apocalyptic number.

It is an amenable number.

18972977354657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18972977354657 is an equidigital number, since it uses as much as digits as its factorization.

18972977354657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5601052800, while the sum is 80.

The spelling of 18972977354657 in words is "eighteen trillion, nine hundred seventy-two billion, nine hundred seventy-seven million, three hundred fifty-four thousand, six hundred fifty-seven".