86978239 has 4 divisors (see below), whose sum is σ = 92094624. Its totient is φ = 81861856.

The previous prime is 86978233. The next prime is 86978299. The reversal of 86978239 is 93287968.

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

It is a cyclic number.

It is not a de Polignac number, because 86978239 - 2⁹ = 86977727 is a prime.

It is a super-2 number, since 2×86978239² = 15130428119082242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86978233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2558167 + ... + 2558200.

It is an arithmetic number, because the mean of its divisors is an integer number (23023656).

Almost surely, 2^86978239 is an apocalyptic number.

86978239 is a deficient number, since it is larger than the sum of its proper divisors (5116385).

86978239 is a wasteful number, since it uses less digits than its factorization.

86978239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5116384.

The product of its digits is 1306368, while the sum is 52.

The square root of 86978239 is about 9326.2124680923. The cubic root of 86978239 is about 443.0678150169.

The spelling of 86978239 in words is "eighty-six million, nine hundred seventy-eight thousand, two hundred thirty-nine".