319881867561 has 9 divisors (see below), whose sum is σ = 462054037341. Its totient is φ = 213253447212.

The previous prime is 319881867541. The next prime is 319881867577. The reversal of 319881867561 is 165768188913.

The square root of 319881867561 is 565581.

It is a perfect power (a square), and thus also a powerful number.

319881867561 is a `hidden beast` number, since 3 + 1 + 9 + 8 + 8 + 1 + 8 + 67 + 561 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 319881867561 - 2⁷ = 319881867433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (319881867511) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1602480 + ... + 1791006.

Almost surely, 2^319881867561 is an apocalyptic number.

319881867561 is the 565581-st square number.

319881867561 is the 282791-st centered octagonal number.

It is an amenable number.

319881867561 is a deficient number, since it is larger than the sum of its proper divisors (142172169780).

319881867561 is an frugal number, since it uses more digits than its factorization.

319881867561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377060 (or 188530 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 63.

The spelling of 319881867561 in words is "three hundred nineteen billion, eight hundred eighty-one million, eight hundred sixty-seven thousand, five hundred sixty-one".