7991019997 has 2 divisors, whose sum is σ = 7991019998. Its totient is φ = 7991019996.

The previous prime is 7991019979. The next prime is 7991020001. The reversal of 7991019997 is 7999101997.

Together with previous prime (7991019979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7740304441 + 250715556 = 87979^2 + 15834^2 .

It is an emirp because it is prime and its reverse (7999101997) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7991019997 - 2²⁷ = 7856802269 is a prime.

It is a super-3 number, since 3×7991019997³ (a number of 31 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7991019917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3995509998 + 3995509999.

It is an arithmetic number, because the mean of its divisors is an integer number (3995509999).

Almost surely, 2^7991019997 is an apocalyptic number.

It is an amenable number.

7991019997 is a deficient number, since it is larger than the sum of its proper divisors (1).

7991019997 is an equidigital number, since it uses as much as digits as its factorization.

7991019997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2893401, while the sum is 61.

The square root of 7991019997 is about 89392.5052619066. The cubic root of 7991019997 is about 1999.2513862403.

The spelling of 7991019997 in words is "seven billion, nine hundred ninety-one million, nineteen thousand, nine hundred ninety-seven".