7997615987 has 2 divisors, whose sum is σ = 7997615988. Its totient is φ = 7997615986.

The previous prime is 7997615933. The next prime is 7997616023. The reversal of 7997615987 is 7895167997.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7997615987 is a prime.

It is a super-2 number, since 2×7997615987² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7997615287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3998807993 + 3998807994.

It is an arithmetic number, because the mean of its divisors is an integer number (3998807994).

Almost surely, 2^7997615987 is an apocalyptic number.

7997615987 is a deficient number, since it is larger than the sum of its proper divisors (1).

7997615987 is an equidigital number, since it uses as much as digits as its factorization.

7997615987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60011280, while the sum is 68.

The square root of 7997615987 is about 89429.3910691558. The cubic root of 7997615987 is about 1999.8013125123.

The spelling of 7997615987 in words is "seven billion, nine hundred ninety-seven million, six hundred fifteen thousand, nine hundred eighty-seven".