68791988761 has 2 divisors, whose sum is σ = 68791988762. Its totient is φ = 68791988760.

The previous prime is 68791988729. The next prime is 68791988807. The reversal of 68791988761 is 16788919786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53485350361 + 15306638400 = 231269^2 + 123720^2 .

It is a cyclic number.

It is not a de Polignac number, because 68791988761 - 2⁵ = 68791988729 is a prime.

It is not a weakly prime, because it can be changed into another prime (68791988701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34395994380 + 34395994381.

It is an arithmetic number, because the mean of its divisors is an integer number (34395994381).

Almost surely, 2^68791988761 is an apocalyptic number.

It is an amenable number.

68791988761 is a deficient number, since it is larger than the sum of its proper divisors (1).

68791988761 is an equidigital number, since it uses as much as digits as its factorization.

68791988761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 73156608, while the sum is 70.

The spelling of 68791988761 in words is "sixty-eight billion, seven hundred ninety-one million, nine hundred eighty-eight thousand, seven hundred sixty-one".