722621 has 4 divisors (see below), whose sum is σ = 726972. Its totient is φ = 718272.

The previous prime is 722611. The next prime is 722633. The reversal of 722621 is 126227.

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 662596 + 60025 = 814^2 + 245^2 .

It is a cyclic number.

It is not a de Polignac number, because 722621 - 2¹⁰ = 721597 is a prime.

It is a super-2 number, since 2×722621² = 1044362219282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 722593 and 722602.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 722621.

It is not an unprimeable number, because it can be changed into a prime (722611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1916 + ... + 2261.

It is an arithmetic number, because the mean of its divisors is an integer number (181743).

2⁷²²⁶²¹ is an apocalyptic number.

It is an amenable number.

722621 is a deficient number, since it is larger than the sum of its proper divisors (4351).

722621 is a wasteful number, since it uses less digits than its factorization.

722621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4350.

The product of its digits is 336, while the sum is 20.

The square root of 722621 is about 850.0711734908. The cubic root of 722621 is about 89.7367202828.

Adding to 722621 its reverse (126227), we get a palindrome (848848).

The spelling of 722621 in words is "seven hundred twenty-two thousand, six hundred twenty-one".