87139878 has 32 divisors (see below), whose sum is σ = 200033280. Its totient is φ = 24790080.

The previous prime is 87139861. The next prime is 87139879. The reversal of 87139878 is 87893178.

It is a self number, because there is not a number n which added to its sum of digits gives 87139878.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87139879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5698 + ... + 14378.

It is an arithmetic number, because the mean of its divisors is an integer number (6251040).

Almost surely, 2^87139878 is an apocalyptic number.

87139878 is an abundant number, since it is smaller than the sum of its proper divisors (112893402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

87139878 is a wasteful number, since it uses less digits than its factorization.

87139878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8932.

The product of its digits is 677376, while the sum is 51.

The square root of 87139878 is about 9334.8742894589. The cubic root of 87139878 is about 443.3421086070.

The spelling of 87139878 in words is "eighty-seven million, one hundred thirty-nine thousand, eight hundred seventy-eight".