718576640721 has 9 divisors (see below), whose sum is σ = 1037947709929. Its totient is φ = 479049398436.

The previous prime is 718576640701. The next prime is 718576640741. The reversal of 718576640721 is 127046675817.

The square root of 718576640721 is 847689.

It is a perfect power (a square), and thus also a powerful number.

718576640721 is a `hidden beast` number, since 7 + 1 + 8 + 576 + 6 + 40 + 7 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (718576640701) and next prime (718576640741).

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 718576640721 - 2¹⁷ = 718576509649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (718576640701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2401786 + ... + 2684348.

Almost surely, 2^718576640721 is an apocalyptic number.

718576640721 is the 847689-th square number.

718576640721 is the 423845-th centered octagonal number.

It is an amenable number.

718576640721 is a deficient number, since it is larger than the sum of its proper divisors (319371069208).

718576640721 is an frugal number, since it uses more digits than its factorization.

718576640721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565132 (or 282566 counting only the distinct ones).

The product of its (nonzero) digits is 3951360, while the sum is 54.

The spelling of 718576640721 in words is "seven hundred eighteen billion, five hundred seventy-six million, six hundred forty thousand, seven hundred twenty-one".