622721 has 4 divisors (see below), whose sum is σ = 679344. Its totient is φ = 566100.

The previous prime is 622709. The next prime is 622723. The reversal of 622721 is 127226.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 622721 - 2¹⁰ = 621697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 622693 and 622702.

It is not an unprimeable number, because it can be changed into a prime (622723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28295 + ... + 28316.

It is an arithmetic number, because the mean of its divisors is an integer number (169836).

2⁶²²⁷²¹ is an apocalyptic number.

It is an amenable number.

622721 is a deficient number, since it is larger than the sum of its proper divisors (56623).

622721 is a wasteful number, since it uses less digits than its factorization.

622721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56622.

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

The square root of 622721 is about 789.1267325341. The cubic root of 622721 is about 85.3947498267.

Adding to 622721 its reverse (127226), we get a palindrome (749947).

The spelling of 622721 in words is "six hundred twenty-two thousand, seven hundred twenty-one".