86921979 has 16 divisors (see below), whose sum is σ = 122897280. Its totient is φ = 54492480.

The previous prime is 86921971. The next prime is 86921983. The reversal of 86921979 is 97912968.

It is a happy number.

It is not a de Polignac number, because 86921979 - 2³ = 86921971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (86921971) 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, 2244 + ... + 13374.

It is an arithmetic number, because the mean of its divisors is an integer number (7681080).

Almost surely, 2^86921979 is an apocalyptic number.

86921979 is a deficient number, since it is larger than the sum of its proper divisors (35975301).

86921979 is a wasteful number, since it uses less digits than its factorization.

86921979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11290.

The product of its digits is 489888, while the sum is 51.

The square root of 86921979 is about 9323.1957503852. The cubic root of 86921979 is about 442.9722647889.

The spelling of 86921979 in words is "eighty-six million, nine hundred twenty-one thousand, nine hundred seventy-nine".