399877904881 has 27 divisors (see below), whose sum is σ = 503770892481. Its totient is φ = 316341383904.

The previous prime is 399877904869. The next prime is 399877904897. The reversal of 399877904881 is 188409778993.

The square root of 399877904881 is 632359.

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

It can be written as a sum of positive squares in 4 ways, for example, as 433680625 + 399444224256 = 20825^2 + 632016^2 .

It is not a de Polignac number, because 399877904881 - 2²³ = 399869516273 is a prime.

It is a super-2 number, since 2×399877904881² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399877904821) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 57541195 + ... + 57548143.

It is an arithmetic number, because the mean of its divisors is an integer number (18658181203).

Almost surely, 2^399877904881 is an apocalyptic number.

399877904881 is the 632359-th square number.

399877904881 is the 316180-th centered octagonal number.

It is an amenable number.

399877904881 is a deficient number, since it is larger than the sum of its proper divisors (103892987600).

399877904881 is an frugal number, since it uses more digits than its factorization.

399877904881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13938 (or 6969 counting only the distinct ones).

The product of its (nonzero) digits is 219469824, while the sum is 73.

The spelling of 399877904881 in words is "three hundred ninety-nine billion, eight hundred seventy-seven million, nine hundred four thousand, eight hundred eighty-one".