715721 has 4 divisors (see below), whose sum is σ = 717444. Its totient is φ = 714000.

The previous prime is 715699. The next prime is 715727. The reversal of 715721 is 127517.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 525625 + 190096 = 725^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 715721 - 2⁶ = 715657 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 715721.

It is not an unprimeable number, because it can be changed into a prime (715727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191 + ... + 1211.

It is an arithmetic number, because the mean of its divisors is an integer number (179361).

2⁷¹⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

715721 is a deficient number, since it is larger than the sum of its proper divisors (1723).

715721 is a wasteful number, since it uses less digits than its factorization.

715721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1722.

The product of its digits is 490, while the sum is 23.

The square root of 715721 is about 846.0029550776. The cubic root of 715721 is about 89.4501871098.

It can be divided in two parts, 715 and 721, that multiplied together give a palindrome (515515).

The spelling of 715721 in words is "seven hundred fifteen thousand, seven hundred twenty-one".