68720995121 has 2 divisors, whose sum is σ = 68720995122. Its totient is φ = 68720995120.

The previous prime is 68720995117. The next prime is 68720995159. The reversal of 68720995121 is 12159902786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65625630625 + 3095364496 = 256175^2 + 55636^2 .

It is a cyclic number.

It is not a de Polignac number, because 68720995121 - 2² = 68720995117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 68720995121.

It is not a weakly prime, because it can be changed into another prime (68720995171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34360497560 + 34360497561.

It is an arithmetic number, because the mean of its divisors is an integer number (34360497561).

Almost surely, 2^68720995121 is an apocalyptic number.

It is an amenable number.

68720995121 is a deficient number, since it is larger than the sum of its proper divisors (1).

68720995121 is an equidigital number, since it uses as much as digits as its factorization.

68720995121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 50.

The spelling of 68720995121 in words is "sixty-eight billion, seven hundred twenty million, nine hundred ninety-five thousand, one hundred twenty-one".