68161661 has 2 divisors, whose sum is σ = 68161662. Its totient is φ = 68161660.

The previous prime is 68161637. The next prime is 68161693. The reversal of 68161661 is 16616186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53377636 + 14784025 = 7306^2 + 3845^2 .

It is a cyclic number.

It is not a de Polignac number, because 68161661 - 2²⁶ = 1052797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68161601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34080830 + 34080831.

It is an arithmetic number, because the mean of its divisors is an integer number (34080831).

Almost surely, 2^68161661 is an apocalyptic number.

It is an amenable number.

68161661 is a deficient number, since it is larger than the sum of its proper divisors (1).

68161661 is an equidigital number, since it uses as much as digits as its factorization.

68161661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 35.

The square root of 68161661 is about 8256.0075702485. The cubic root of 68161661 is about 408.4887073669.

The spelling of 68161661 in words is "sixty-eight million, one hundred sixty-one thousand, six hundred sixty-one".