864291591 has 18 divisors (see below), whose sum is σ = 1267094088. Its totient is φ = 567590520.

The previous prime is 864291583. The next prime is 864291607. The reversal of 864291591 is 195192468.

It is not a de Polignac number, because 864291591 - 2³ = 864291583 is a prime.

It is a super-2 number, since 2×864291591² = 1493999908546622562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864291541) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 742576 + ... + 743738.

It is an arithmetic number, because the mean of its divisors is an integer number (70394116).

Almost surely, 2^864291591 is an apocalyptic number.

864291591 is a deficient number, since it is larger than the sum of its proper divisors (402802497).

864291591 is an equidigital number, since it uses as much as digits as its factorization.

864291591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2403 (or 1237 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 864291591 is about 29398.8365586123. The cubic root of 864291591 is about 952.5477653935.

The spelling of 864291591 in words is "eight hundred sixty-four million, two hundred ninety-one thousand, five hundred ninety-one".