7531721 has 2 divisors, whose sum is σ = 7531722. Its totient is φ = 7531720.

The previous prime is 7531717. The next prime is 7531739. The reversal of 7531721 is 1271357.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6553600 + 978121 = 2560^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 7531721 - 2² = 7531717 is a prime.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (7534721) 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, 3765860 + 3765861.

It is an arithmetic number, because the mean of its divisors is an integer number (3765861).

Almost surely, 2^7531721 is an apocalyptic number.

It is an amenable number.

7531721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7531721 is an equidigital number, since it uses as much as digits as its factorization.

7531721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1470, while the sum is 26.

The square root of 7531721 is about 2744.3981125194. The cubic root of 7531721 is about 196.0189572806.

The spelling of 7531721 in words is "seven million, five hundred thirty-one thousand, seven hundred twenty-one".