165404312657 has 2 divisors, whose sum is σ = 165404312658. Its totient is φ = 165404312656.

The previous prime is 165404312653. The next prime is 165404312779. The reversal of 165404312657 is 756213404561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156581655616 + 8822657041 = 395704^2 + 93929^2 .

It is a cyclic number.

It is not a de Polignac number, because 165404312657 - 2² = 165404312653 is a prime.

It is a super-2 number, since 2×165404312657² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165404312651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82702156328 + 82702156329.

It is an arithmetic number, because the mean of its divisors is an integer number (82702156329).

Almost surely, 2^165404312657 is an apocalyptic number.

It is an amenable number.

165404312657 is a deficient number, since it is larger than the sum of its proper divisors (1).

165404312657 is an equidigital number, since it uses as much as digits as its factorization.

165404312657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 44.

The spelling of 165404312657 in words is "one hundred sixty-five billion, four hundred four million, three hundred twelve thousand, six hundred fifty-seven".