79997999987 has 2 divisors, whose sum is σ = 79997999988. Its totient is φ = 79997999986.

The previous prime is 79997999923. The next prime is 79998000001. The reversal of 79997999987 is 78999979997.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 79997999987 - 2⁶ = 79997999923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 79997999896 and 79997999905.

It is not a weakly prime, because it can be changed into another prime (79997999687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39998999993 + 39998999994.

It is an arithmetic number, because the mean of its divisors is an integer number (39998999994).

Almost surely, 2^79997999987 is an apocalyptic number.

79997999987 is a deficient number, since it is larger than the sum of its proper divisors (1).

79997999987 is an equidigital number, since it uses as much as digits as its factorization.

79997999987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13124466936, while the sum is 92.

The spelling of 79997999987 in words is "seventy-nine billion, nine hundred ninety-seven million, nine hundred ninety-nine thousand, nine hundred eighty-seven".