721715 has 16 divisors (see below), whose sum is σ = 933120. Its totient is φ = 534240.

The previous prime is 721709. The next prime is 721733. The reversal of 721715 is 517127.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-721715 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6692 + ... + 6798.

It is an arithmetic number, because the mean of its divisors is an integer number (58320).

2⁷²¹⁷¹⁵ is an apocalyptic number.

721715 is a deficient number, since it is larger than the sum of its proper divisors (211405).

721715 is a wasteful number, since it uses less digits than its factorization.

721715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202.

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

The square root of 721715 is about 849.5381097985. The cubic root of 721715 is about 89.6992015512.

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

The spelling of 721715 in words is "seven hundred twenty-one thousand, seven hundred fifteen".