87640665 has 96 divisors (see below), whose sum is σ = 173352960. Its totient is φ = 37650816.

The previous prime is 87640633. The next prime is 87640669. The reversal of 87640665 is 56604678.

It is a happy number.

It is not a de Polignac number, because 87640665 - 2⁵ = 87640633 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87640669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1485406 + ... + 1485464.

It is an arithmetic number, because the mean of its divisors is an integer number (1805760).

Almost surely, 2^87640665 is an apocalyptic number.

It is an amenable number.

87640665 is a deficient number, since it is larger than the sum of its proper divisors (85712295).

87640665 is a wasteful number, since it uses less digits than its factorization.

87640665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The square root of 87640665 is about 9361.6593080500. The cubic root of 87640665 is about 444.1897725817.

The spelling of 87640665 in words is "eighty-seven million, six hundred forty thousand, six hundred sixty-five".