405865873881 has 40 divisors (see below), whose sum is σ = 665250977160. Its totient is φ = 245051059968.

The previous prime is 405865873871. The next prime is 405865873901. The reversal of 405865873881 is 188378568504.

405865873881 is a `hidden beast` number, since 40 + 5 + 8 + 6 + 587 + 3 + 8 + 8 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 85956857856 + 319909016025 = 293184^2 + 565605^2 .

It is not a de Polignac number, because 405865873881 - 2⁵ = 405865873849 is a prime.

It is a super-2 number, since 2×405865873881² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (405865873841) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3580396 + ... + 3692013.

It is an arithmetic number, because the mean of its divisors is an integer number (16631274429).

Almost surely, 2^405865873881 is an apocalyptic number.

It is an amenable number.

405865873881 is a deficient number, since it is larger than the sum of its proper divisors (259385103279).

405865873881 is a wasteful number, since it uses less digits than its factorization.

405865873881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7272487 (or 7272478 counting only the distinct ones).

The product of its (nonzero) digits is 51609600, while the sum is 63.

The spelling of 405865873881 in words is "four hundred five billion, eight hundred sixty-five million, eight hundred seventy-three thousand, eight hundred eighty-one".