7091681 has 2 divisors, whose sum is σ = 7091682. Its totient is φ = 7091680.

The previous prime is 7091671. The next prime is 7091683. The reversal of 7091681 is 1861907.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6477025 + 614656 = 2545^2 + 784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7091681 is a prime.

It is a super-2 number, since 2×7091681² = 100583878811522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 7091683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7091683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3545840 + 3545841.

It is an arithmetic number, because the mean of its divisors is an integer number (3545841).

Almost surely, 2^7091681 is an apocalyptic number.

It is an amenable number.

7091681 is a deficient number, since it is larger than the sum of its proper divisors (1).

7091681 is an equidigital number, since it uses as much as digits as its factorization.

7091681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 7091681 is about 2663.0210288317. The cubic root of 7091681 is about 192.1246387624.

The spelling of 7091681 in words is "seven million, ninety-one thousand, six hundred eighty-one".