86231891 has 4 divisors (see below), whose sum is σ = 86309400. Its totient is φ = 86154384.

The previous prime is 86231869. The next prime is 86231911. The reversal of 86231891 is 19813268.

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 86231891 - 2¹⁸ = 85969747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (86231851) 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, 37061 + ... + 39318.

It is an arithmetic number, because the mean of its divisors is an integer number (21577350).

Almost surely, 2^86231891 is an apocalyptic number.

86231891 is a deficient number, since it is larger than the sum of its proper divisors (77509).

86231891 is a wasteful number, since it uses less digits than its factorization.

86231891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77508.

The product of its digits is 20736, while the sum is 38.

The square root of 86231891 is about 9286.1128035363. The cubic root of 86231891 is about 441.7968719865.

The spelling of 86231891 in words is "eighty-six million, two hundred thirty-one thousand, eight hundred ninety-one".