7681645997 has 2 divisors, whose sum is σ = 7681645998. Its totient is φ = 7681645996.

The previous prime is 7681645991. The next prime is 7681646029. The reversal of 7681645997 is 7995461867.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6180160996 + 1501485001 = 78614^2 + 38749^2 .

It is an emirp because it is prime and its reverse (7995461867) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7681645997 - 2²⁴ = 7664868781 is a prime.

It is a super-2 number, since 2×7681645997² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7681645991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3840822998 + 3840822999.

It is an arithmetic number, because the mean of its divisors is an integer number (3840822999).

Almost surely, 2^7681645997 is an apocalyptic number.

It is an amenable number.

7681645997 is a deficient number, since it is larger than the sum of its proper divisors (1).

7681645997 is an equidigital number, since it uses as much as digits as its factorization.

7681645997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 62.

The square root of 7681645997 is about 87644.9998402647. Note that the first 3 decimals coincide. The cubic root of 7681645997 is about 1973.1106000097.

The spelling of 7681645997 in words is "seven billion, six hundred eighty-one million, six hundred forty-five thousand, nine hundred ninety-seven".