40404618081 has 9 divisors (see below), whose sum is σ = 58363097169. Its totient is φ = 26936010036.

The previous prime is 40404618047. The next prime is 40404618103. The reversal of 40404618081 is 18081640404.

The square root of 40404618081 is 201009.

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

40404618081 is a `hidden beast` number, since 4 + 0 + 40 + 461 + 80 + 81 = 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 40404618081 - 2²³ = 40396229473 is a prime.

It is a super-2 number, since 2×40404618081² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40404618031) 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, 569526 + ... + 636528.

Almost surely, 2^40404618081 is an apocalyptic number.

40404618081 is the 201009-th square number.

40404618081 is the 100505-th centered octagonal number.

It is an amenable number.

40404618081 is a deficient number, since it is larger than the sum of its proper divisors (17958479088).

40404618081 is an frugal number, since it uses more digits than its factorization.

40404618081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134012 (or 67006 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

Multiplying 40404618081 by its sum of digits (36), we get a square (1454566250916 = 1206054²).

The spelling of 40404618081 in words is "forty billion, four hundred four million, six hundred eighteen thousand, eighty-one".