68639657 has 2 divisors, whose sum is σ = 68639658. Its totient is φ = 68639656.

The previous prime is 68639651. The next prime is 68639687. The reversal of 68639657 is 75693686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53304601 + 15335056 = 7301^2 + 3916^2 .

It is a cyclic number.

It is not a de Polignac number, because 68639657 - 2⁸ = 68639401 is a prime.

It is a super-2 number, since 2×68639657² = 9422805026155298, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68639651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34319828 + 34319829.

It is an arithmetic number, because the mean of its divisors is an integer number (34319829).

Almost surely, 2^68639657 is an apocalyptic number.

It is an amenable number.

68639657 is a deficient number, since it is larger than the sum of its proper divisors (1).

68639657 is an equidigital number, since it uses as much as digits as its factorization.

68639657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 50.

The square root of 68639657 is about 8284.9053706123. The cubic root of 68639657 is about 409.4413509919.

It can be divided in two parts, 68639 and 657, that added together give a palindrome (69296).

The spelling of 68639657 in words is "sixty-eight million, six hundred thirty-nine thousand, six hundred fifty-seven".