864101721 has 64 divisors (see below), whose sum is σ = 1454284800. Its totient is φ = 454406400.

The previous prime is 864101717. The next prime is 864101731. The reversal of 864101721 is 127101468.

It is not a de Polignac number, because 864101721 - 2² = 864101717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (864101731) 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 63 ways as a sum of consecutive naturals, for example, 821646 + ... + 822696.

It is an arithmetic number, because the mean of its divisors is an integer number (22723200).

Almost surely, 2^864101721 is an apocalyptic number.

It is an amenable number.

864101721 is a deficient number, since it is larger than the sum of its proper divisors (590183079).

864101721 is a wasteful number, since it uses less digits than its factorization.

864101721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1125 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 864101721 is about 29395.6071718208. The cubic root of 864101721 is about 952.4780074971.

The spelling of 864101721 in words is "eight hundred sixty-four million, one hundred one thousand, seven hundred twenty-one".