40003600081 has 3 divisors (see below), whose sum is σ = 40003800091. Its totient is φ = 40003400072.

The previous prime is 40003600061. The next prime is 40003600093. The reversal of 40003600081 is 18000630004.

The square root of 40003600081 is 200009.

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

40003600081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2708265681 + 37295334400 = 52041^2 + 193120^2 .

It is a de Polignac number, because none of the positive numbers 2^k-40003600081 is a prime.

It is a super-2 number, since 2×40003600081² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40003600061) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 100005 + ... + 300013.

Almost surely, 2^40003600081 is an apocalyptic number.

40003600081 is the 200009-th square number.

40003600081 is the 100005-th centered octagonal number.

It is an amenable number.

40003600081 is a deficient number, since it is larger than the sum of its proper divisors (200010).

40003600081 is an frugal number, since it uses more digits than its factorization.

40003600081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400018 (or 200009 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

Multiplying 40003600081 by its product of nonzero digits (576), we get a square (23042073646656 = 4800216²).

The spelling of 40003600081 in words is "forty billion, three million, six hundred thousand, eighty-one".