972721 has 2 divisors, whose sum is σ = 972722. Its totient is φ = 972720.

The previous prime is 972701. The next prime is 972787. The reversal of 972721 is 127279.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 960400 + 12321 = 980^2 + 111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-972721 is a prime.

It is a super-2 number, since 2×972721² = 1892372287682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 972721.

It is not a weakly prime, because it can be changed into another prime (972701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 486360 + 486361.

It is an arithmetic number, because the mean of its divisors is an integer number (486361).

2⁹⁷²⁷²¹ is an apocalyptic number.

It is an amenable number.

972721 is a deficient number, since it is larger than the sum of its proper divisors (1).

972721 is an equidigital number, since it uses as much as digits as its factorization.

972721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 28.

The square root of 972721 is about 986.2661912486. The cubic root of 972721 is about 99.0823041042.

The spelling of 972721 in words is "nine hundred seventy-two thousand, seven hundred twenty-one".