68716891 has 2 divisors, whose sum is σ = 68716892. Its totient is φ = 68716890.

The previous prime is 68716877. The next prime is 68716897. The reversal of 68716891 is 19861786.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68716891 - 2⁹ = 68716379 is a prime.

It is a super-2 number, since 2×68716891² = 9444022217411762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68716897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34358445 + 34358446.

It is an arithmetic number, because the mean of its divisors is an integer number (34358446).

Almost surely, 2^68716891 is an apocalyptic number.

68716891 is a deficient number, since it is larger than the sum of its proper divisors (1).

68716891 is an equidigital number, since it uses as much as digits as its factorization.

68716891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 46.

The square root of 68716891 is about 8289.5651876320. The cubic root of 68716891 is about 409.5948625397.

It can be divided in two parts, 687 and 16891, that added together give a triangular number (17578 = T₁₈₇).

The spelling of 68716891 in words is "sixty-eight million, seven hundred sixteen thousand, eight hundred ninety-one".