40000081 has 4 divisors (see below), whose sum is σ = 43636464. Its totient is φ = 36363700.

The previous prime is 40000061. The next prime is 40000123. The reversal of 40000081 is 18000004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40000081 - 2²³ = 31611473 is a prime.

It is a super-2 number, since 2×40000081² = 3200012960013122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40000021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1818175 + ... + 1818196.

It is an arithmetic number, because the mean of its divisors is an integer number (10909116).

Almost surely, 2^40000081 is an apocalyptic number.

It is an amenable number.

40000081 is a deficient number, since it is larger than the sum of its proper divisors (3636383).

40000081 is a wasteful number, since it uses less digits than its factorization.

40000081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3636382.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 40000081 is about 6324.5617239458. The cubic root of 40000081 is about 341.9954201819.

Adding to 40000081 its reverse (18000004), we get a palindrome (58000085).

The spelling of 40000081 in words is "forty million, eighty-one", and thus it is an aban number and an uban number.