87666639 has 8 divisors (see below), whose sum is σ = 121971072. Its totient is φ = 55903320.

The previous prime is 87666617. The next prime is 87666647. The reversal of 87666639 is 93666678.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 87666639 - 2⁷ = 87666511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 87666591 and 87666600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87666679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 635197 + ... + 635334.

It is an arithmetic number, because the mean of its divisors is an integer number (15246384).

Almost surely, 2^87666639 is an apocalyptic number.

87666639 is a deficient number, since it is larger than the sum of its proper divisors (34304433).

87666639 is a wasteful number, since it uses less digits than its factorization.

87666639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1270557.

The product of its digits is 1959552, while the sum is 51.

The square root of 87666639 is about 9363.0464593529. The cubic root of 87666639 is about 444.2336496471.

The spelling of 87666639 in words is "eighty-seven million, six hundred sixty-six thousand, six hundred thirty-nine".