399765972905 has 16 divisors (see below), whose sum is σ = 547010092944. Its totient is φ = 277846394880.

The previous prime is 399765972841. The next prime is 399765972919. The reversal of 399765972905 is 509279567993.

It can be written as a sum of positive squares in 8 ways, for example, as 14526034576 + 385239938329 = 120524^2 + 620677^2 .

It is not a de Polignac number, because 399765972905 - 2⁶ = 399765972841 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 180888476 + ... + 180890685.

It is an arithmetic number, because the mean of its divisors is an integer number (34188130809).

Almost surely, 2^399765972905 is an apocalyptic number.

It is an amenable number.

399765972905 is a deficient number, since it is larger than the sum of its proper divisors (147244120039).

399765972905 is a wasteful number, since it uses less digits than its factorization.

399765972905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361779196.

The product of its (nonzero) digits is 289340100, while the sum is 71.

The spelling of 399765972905 in words is "three hundred ninety-nine billion, seven hundred sixty-five million, nine hundred seventy-two thousand, nine hundred five".