7272721 has 2 divisors, whose sum is σ = 7272722. Its totient is φ = 7272720.

The previous prime is 7272697. The next prime is 7272737. The reversal of 7272721 is 1272727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6864400 + 408321 = 2620^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 7272721 - 2⁵ = 7272689 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

7272721 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 7272721.

It is not a weakly prime, because it can be changed into another prime (7272751) 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, 3636360 + 3636361.

It is an arithmetic number, because the mean of its divisors is an integer number (3636361).

Almost surely, 2^7272721 is an apocalyptic number.

It is an amenable number.

7272721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7272721 is an equidigital number, since it uses as much as digits as its factorization.

7272721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2744, while the sum is 28.

The square root of 7272721 is about 2696.7982868580. The cubic root of 7272721 is about 193.7458055283.

The spelling of 7272721 in words is "seven million, two hundred seventy-two thousand, seven hundred twenty-one".