40081665 has 64 divisors (see below), whose sum is σ = 74462976. Its totient is φ = 18235392.

The previous prime is 40081651. The next prime is 40081669. The reversal of 40081665 is 56618004.

It is not a de Polignac number, because 40081665 - 2⁴ = 40081649 is a prime.

It is a zygodrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (40081669) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 354649 + ... + 354761.

It is an arithmetic number, because the mean of its divisors is an integer number (1163484).

Almost surely, 2^40081665 is an apocalyptic number.

It is an amenable number.

40081665 is a deficient number, since it is larger than the sum of its proper divisors (34381311).

40081665 is a wasteful number, since it uses less digits than its factorization.

40081665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 40081665 is about 6331.0082135470. The cubic root of 40081665 is about 342.2277731003.

Adding to 40081665 its reverse (56618004), we get a palindrome (96699669).

The spelling of 40081665 in words is "forty million, eighty-one thousand, six hundred sixty-five".