406394775081 has 27 divisors (see below), whose sum is σ = 613713147229. Its totient is φ = 259122241752.

The previous prime is 406394775071. The next prime is 406394775097. The reversal of 406394775081 is 180577493604.

The square root of 406394775081 is 637491.

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

406394775081 is a `hidden beast` number, since 4 + 0 + 63 + 9 + 4 + 77 + 508 + 1 = 666.

It is not a de Polignac number, because 406394775081 - 2¹¹ = 406394773033 is a prime.

It is a super-2 number, since 2×406394775081² (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 (406394775011) 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, 43982260 + ... + 43991498.

Almost surely, 2^406394775081 is an apocalyptic number.

406394775081 is the 637491-st square number.

406394775081 is the 318746-th centered octagonal number.

It is an amenable number.

406394775081 is a deficient number, since it is larger than the sum of its proper divisors (207318372148).

406394775081 is an frugal number, since it uses more digits than its factorization.

406394775081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18530 (or 9265 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 406394775081 in words is "four hundred six billion, three hundred ninety-four million, seven hundred seventy-five thousand, eighty-one".