68508731 has 2 divisors, whose sum is σ = 68508732. Its totient is φ = 68508730.

The previous prime is 68508709. The next prime is 68508733. The reversal of 68508731 is 13780586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68508731 - 2¹⁰ = 68507707 is a prime.

It is a super-2 number, since 2×68508731² = 9386892446460722, which contains 22 as substring.

Together with 68508733, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (68508733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34254365 + 34254366.

It is an arithmetic number, because the mean of its divisors is an integer number (34254366).

Almost surely, 2^68508731 is an apocalyptic number.

68508731 is a deficient number, since it is larger than the sum of its proper divisors (1).

68508731 is an equidigital number, since it uses as much as digits as its factorization.

68508731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 68508731 is about 8277.0001208167. Note that the first 3 decimals coincide. The cubic root of 68508731 is about 409.1808570804.

The spelling of 68508731 in words is "sixty-eight million, five hundred eight thousand, seven hundred thirty-one".