87979985 has 4 divisors (see below), whose sum is σ = 105575988. Its totient is φ = 70383984.

The previous prime is 87979949. The next prime is 87979987. The reversal of 87979985 is 58997978.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52171729 + 35808256 = 7223^2 + 5984^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87979985 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87979987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8797994 + ... + 8798003.

It is an arithmetic number, because the mean of its divisors is an integer number (26393997).

Almost surely, 2^87979985 is an apocalyptic number.

It is an amenable number.

87979985 is a deficient number, since it is larger than the sum of its proper divisors (17596003).

87979985 is a wasteful number, since it uses less digits than its factorization.

87979985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17596002.

The product of its digits is 11430720, while the sum is 62.

The square root of 87979985 is about 9379.7646558962. The cubic root of 87979985 is about 444.7622936164.

The spelling of 87979985 in words is "eighty-seven million, nine hundred seventy-nine thousand, nine hundred eighty-five".