722657 has 4 divisors (see below), whose sum is σ = 778260. Its totient is φ = 667056.

The previous prime is 722639. The next prime is 722663. The reversal of 722657 is 756227.

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 43681 + 678976 = 209^2 + 824^2 .

It is not a de Polignac number, because 722657 - 2¹⁶ = 657121 is a prime.

It is an Ulam number.

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 722657.

It is not an unprimeable number, because it can be changed into a prime (722257) 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, 27782 + ... + 27807.

It is an arithmetic number, because the mean of its divisors is an integer number (194565).

2⁷²²⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

722657 is a deficient number, since it is larger than the sum of its proper divisors (55603).

722657 is a wasteful number, since it uses less digits than its factorization.

722657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55602.

The product of its digits is 5880, while the sum is 29.

The square root of 722657 is about 850.0923479246. The cubic root of 722657 is about 89.7382104454.

The spelling of 722657 in words is "seven hundred twenty-two thousand, six hundred fifty-seven".