864870721 has 16 divisors (see below), whose sum is σ = 1026563328. Its totient is φ = 718272000.

The previous prime is 864870719. The next prime is 864870731. The reversal of 864870721 is 127078468.

It is a cyclic number.

It is not a de Polignac number, because 864870721 - 2¹ = 864870719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (864870731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17305 + ... + 45046.

It is an arithmetic number, because the mean of its divisors is an integer number (64160208).

Almost surely, 2^864870721 is an apocalyptic number.

It is an amenable number.

864870721 is a deficient number, since it is larger than the sum of its proper divisors (161692607).

864870721 is a wasteful number, since it uses less digits than its factorization.

864870721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62472.

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 864870721 is about 29408.6844486454. The cubic root of 864870721 is about 952.7604736298.

The spelling of 864870721 in words is "eight hundred sixty-four million, eight hundred seventy thousand, seven hundred twenty-one".