68517931 has 2 divisors, whose sum is σ = 68517932. Its totient is φ = 68517930.

The previous prime is 68517919. The next prime is 68517941. The reversal of 68517931 is 13971586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68517931 - 2¹⁷ = 68386859 is a prime.

It is a super-2 number, since 2×68517931² = 9389413737041522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68517901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34258965 + 34258966.

It is an arithmetic number, because the mean of its divisors is an integer number (34258966).

Almost surely, 2^68517931 is an apocalyptic number.

68517931 is a deficient number, since it is larger than the sum of its proper divisors (1).

68517931 is an equidigital number, since it uses as much as digits as its factorization.

68517931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 40.

The square root of 68517931 is about 8277.5558590685. Note that the first 3 decimals coincide. The cubic root of 68517931 is about 409.1991724850.

The spelling of 68517931 in words is "sixty-eight million, five hundred seventeen thousand, nine hundred thirty-one".