165404312779 has 2 divisors, whose sum is σ = 165404312780. Its totient is φ = 165404312778.

The previous prime is 165404312657. The next prime is 165404312789. The reversal of 165404312779 is 977213404561.

It is a strong prime.

It is an emirp because it is prime and its reverse (977213404561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165404312779 - 2⁷ = 165404312651 is a prime.

It is not a weakly prime, because it can be changed into another prime (165404312789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82702156389 + 82702156390.

It is an arithmetic number, because the mean of its divisors is an integer number (82702156390).

Almost surely, 2^165404312779 is an apocalyptic number.

165404312779 is a deficient number, since it is larger than the sum of its proper divisors (1).

165404312779 is an equidigital number, since it uses as much as digits as its factorization.

165404312779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1270080, while the sum is 49.

The spelling of 165404312779 in words is "one hundred sixty-five billion, four hundred four million, three hundred twelve thousand, seven hundred seventy-nine".