718829721 has 27 divisors (see below), whose sum is σ = 1081457013. Its totient is φ = 477772020.

The previous prime is 718829711. The next prime is 718829723. The reversal of 718829721 is 127928817.

The square root of 718829721 is 26811.

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

718829721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (27).

It is not a de Polignac number, because 718829721 - 2⁵ = 718829689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (718829723) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2171526 + ... + 2171856.

Almost surely, 2^718829721 is an apocalyptic number.

718829721 is the 26811-st square number.

718829721 is the 13406-th centered octagonal number.

It is an amenable number.

718829721 is a deficient number, since it is larger than the sum of its proper divisors (362627292).

718829721 is an frugal number, since it uses more digits than its factorization.

718829721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686 (or 334 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The cubic root of 718829721 is about 895.7950846930.

Multiplying 718829721 by its product of digits (112896), we get a square (81153000182016 = 9008496²).

The spelling of 718829721 in words is "seven hundred eighteen million, eight hundred twenty-nine thousand, seven hundred twenty-one".