864533391 has 8 divisors (see below), whose sum is σ = 1163286960. Its totient is φ = 571067712.

The previous prime is 864533387. The next prime is 864533393. The reversal of 864533391 is 193335468.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 864533391 - 2² = 864533387 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864533393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1321590 + ... + 1322243.

It is an arithmetic number, because the mean of its divisors is an integer number (145410870).

Almost surely, 2^864533391 is an apocalyptic number.

864533391 is a deficient number, since it is larger than the sum of its proper divisors (298753569).

864533391 is a wasteful number, since it uses less digits than its factorization.

864533391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2643945.

The product of its digits is 233280, while the sum is 42.

The square root of 864533391 is about 29402.9486786615. The cubic root of 864533391 is about 952.6365874902.

The spelling of 864533391 in words is "eight hundred sixty-four million, five hundred thirty-three thousand, three hundred ninety-one".