867312721 has 16 divisors (see below), whose sum is σ = 953377920. Its totient is φ = 782478720.

The previous prime is 867312713. The next prime is 867312737. The reversal of 867312721 is 127213768.

It is a cyclic number.

It is not a de Polignac number, because 867312721 - 2³ = 867312713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (867312751) 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, 1182871 + ... + 1183603.

It is an arithmetic number, because the mean of its divisors is an integer number (59586120).

Almost surely, 2^867312721 is an apocalyptic number.

It is an amenable number.

867312721 is a deficient number, since it is larger than the sum of its proper divisors (86065199).

867312721 is a wasteful number, since it uses less digits than its factorization.

867312721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416.

The product of its digits is 28224, while the sum is 37.

The square root of 867312721 is about 29450.1735308979. The cubic root of 867312721 is about 953.6563511516.

The spelling of 867312721 in words is "eight hundred sixty-seven million, three hundred twelve thousand, seven hundred twenty-one".