665584444961 has 2 divisors, whose sum is σ = 665584444962. Its totient is φ = 665584444960.

The previous prime is 665584444913. The next prime is 665584444999. The reversal of 665584444961 is 169444485566.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 497673811600 + 167910633361 = 705460^2 + 409769^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665584444961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665584444894 and 665584444903.

It is not a weakly prime, because it can be changed into another prime (665584441961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332792222480 + 332792222481.

It is an arithmetic number, because the mean of its divisors is an integer number (332792222481).

Almost surely, 2^665584444961 is an apocalyptic number.

It is an amenable number.

665584444961 is a deficient number, since it is larger than the sum of its proper divisors (1).

665584444961 is an equidigital number, since it uses as much as digits as its factorization.

665584444961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 99532800, while the sum is 62.

The spelling of 665584444961 in words is "six hundred sixty-five billion, five hundred eighty-four million, four hundred forty-four thousand, nine hundred sixty-one".