7015721 has 2 divisors, whose sum is σ = 7015722. Its totient is φ = 7015720.

The previous prime is 7015717. The next prime is 7015733. The reversal of 7015721 is 1275107.

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., 6864400 + 151321 = 2620^2 + 389^2 .

It is an emirp because it is prime and its reverse (1275107) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7015721 - 2² = 7015717 is a prime.

It is a super-2 number, since 2×7015721² = 98440682299682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7015711) 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, 3507860 + 3507861.

It is an arithmetic number, because the mean of its divisors is an integer number (3507861).

Almost surely, 2^7015721 is an apocalyptic number.

It is an amenable number.

7015721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7015721 is an equidigital number, since it uses as much as digits as its factorization.

7015721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 7015721 is about 2648.7206345706. The cubic root of 7015721 is about 191.4362168763.

The spelling of 7015721 in words is "seven million, fifteen thousand, seven hundred twenty-one".