68215677991 has 2 divisors, whose sum is σ = 68215677992. Its totient is φ = 68215677990.

The previous prime is 68215677913. The next prime is 68215678067. The reversal of 68215677991 is 19977651286.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68215677991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68215677191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34107838995 + 34107838996.

It is an arithmetic number, because the mean of its divisors is an integer number (34107838996).

Almost surely, 2^68215677991 is an apocalyptic number.

68215677991 is a deficient number, since it is larger than the sum of its proper divisors (1).

68215677991 is an equidigital number, since it uses as much as digits as its factorization.

68215677991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11430720, while the sum is 61.

The spelling of 68215677991 in words is "sixty-eight billion, two hundred fifteen million, six hundred seventy-seven thousand, nine hundred ninety-one".