722921 has 2 divisors, whose sum is σ = 722922. Its totient is φ = 722920.

The previous prime is 722903. The next prime is 722933. The reversal of 722921 is 129227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 698896 + 24025 = 836^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 722921 - 2¹⁸ = 460777 is a prime.

It is a super-2 number, since 2×722921² = 1045229544482, which contains 22 as substring.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 722921.

It is not a weakly prime, because it can be changed into another prime (722971) 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 as a sum of consecutive naturals, namely, 361460 + 361461.

It is an arithmetic number, because the mean of its divisors is an integer number (361461).

2⁷²²⁹²¹ is an apocalyptic number.

It is an amenable number.

722921 is a deficient number, since it is larger than the sum of its proper divisors (1).

722921 is an equidigital number, since it uses as much as digits as its factorization.

722921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 23.

The square root of 722921 is about 850.2476109934. The cubic root of 722921 is about 89.7491367923.

The spelling of 722921 in words is "seven hundred twenty-two thousand, nine hundred twenty-one".