7645681 has 2 divisors, whose sum is σ = 7645682. Its totient is φ = 7645680.

The previous prime is 7645669. The next prime is 7645691. The reversal of 7645681 is 1865467.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5640625 + 2005056 = 2375^2 + 1416^2 .

It is an emirp because it is prime and its reverse (1865467) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7645681 - 2¹¹ = 7643633 is a prime.

It is a super-2 number, since 2×7645681² = 116912875907522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7645681.

It is not a weakly prime, because it can be changed into another prime (7645601) 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, 3822840 + 3822841.

It is an arithmetic number, because the mean of its divisors is an integer number (3822841).

Almost surely, 2^7645681 is an apocalyptic number.

It is an amenable number.

7645681 is a deficient number, since it is larger than the sum of its proper divisors (1).

7645681 is an equidigital number, since it uses as much as digits as its factorization.

7645681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 37.

The square root of 7645681 is about 2765.0824580833. The cubic root of 7645681 is about 197.0026453990.

The spelling of 7645681 in words is "seven million, six hundred forty-five thousand, six hundred eighty-one".