726957721 has 8 divisors (see below), whose sum is σ = 835400384. Its totient is φ = 619662960.

The previous prime is 726957709. The next prime is 726957773. The reversal of 726957721 is 127759627.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 726957721 - 2²⁵ = 693403289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (726957521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285615 + ... + 288148.

It is an arithmetic number, because the mean of its divisors is an integer number (104425048).

Almost surely, 2^726957721 is an apocalyptic number.

It is an amenable number.

726957721 is a deficient number, since it is larger than the sum of its proper divisors (108442663).

726957721 is a wasteful number, since it uses less digits than its factorization.

726957721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573951.

The product of its digits is 370440, while the sum is 46.

The square root of 726957721 is about 26962.1534933692. The cubic root of 726957721 is about 899.1587699142.

The spelling of 726957721 in words is "seven hundred twenty-six million, nine hundred fifty-seven thousand, seven hundred twenty-one".