864814721 has 4 divisors (see below), whose sum is σ = 876661572. Its totient is φ = 852967872.

The previous prime is 864814669. The next prime is 864814733. The reversal of 864814721 is 127418468.

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

It can be written as a sum of positive squares in 2 ways, for example, as 295324225 + 569490496 = 17185^2 + 23864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-864814721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (864810721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5923316 + ... + 5923461.

It is an arithmetic number, because the mean of its divisors is an integer number (219165393).

Almost surely, 2^864814721 is an apocalyptic number.

It is an amenable number.

864814721 is a deficient number, since it is larger than the sum of its proper divisors (11846851).

864814721 is a wasteful number, since it uses less digits than its factorization.

864814721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11846850.

The product of its digits is 86016, while the sum is 41.

The square root of 864814721 is about 29407.7323335207. The cubic root of 864814721 is about 952.7399095784.

The spelling of 864814721 in words is "eight hundred sixty-four million, eight hundred fourteen thousand, seven hundred twenty-one".