68931661 has 2 divisors, whose sum is σ = 68931662. Its totient is φ = 68931660.

The previous prime is 68931649. The next prime is 68931671. The reversal of 68931661 is 16613986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46321636 + 22610025 = 6806^2 + 4755^2 .

It is a cyclic number.

It is not a de Polignac number, because 68931661 - 2¹¹ = 68929613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68931671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34465830 + 34465831.

It is an arithmetic number, because the mean of its divisors is an integer number (34465831).

Almost surely, 2^68931661 is an apocalyptic number.

It is an amenable number.

68931661 is a deficient number, since it is larger than the sum of its proper divisors (1).

68931661 is an equidigital number, since it uses as much as digits as its factorization.

68931661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 40.

The square root of 68931661 is about 8302.5093194769. The cubic root of 68931661 is about 410.0211391044.

The spelling of 68931661 in words is "sixty-eight million, nine hundred thirty-one thousand, six hundred sixty-one".