7993721 has 2 divisors, whose sum is σ = 7993722. Its totient is φ = 7993720.

The previous prime is 7993717. The next prime is 7993747. The reversal of 7993721 is 1273997.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7639696 + 354025 = 2764^2 + 595^2 .

It is a cyclic number.

It is not a de Polignac number, because 7993721 - 2² = 7993717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7993781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3996860 + 3996861.

It is an arithmetic number, because the mean of its divisors is an integer number (3996861).

Almost surely, 2^7993721 is an apocalyptic number.

It is an amenable number.

7993721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7993721 is an equidigital number, since it uses as much as digits as its factorization.

7993721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23814, while the sum is 38.

The square root of 7993721 is about 2827.3169259918. The cubic root of 7993721 is about 199.9476613045.

The spelling of 7993721 in words is "seven million, nine hundred ninety-three thousand, seven hundred twenty-one".