68315921 has 2 divisors, whose sum is σ = 68315922. Its totient is φ = 68315920.

The previous prime is 68315893. The next prime is 68315941. The reversal of 68315921 is 12951386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58736896 + 9579025 = 7664^2 + 3095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68315921 is a prime.

It is not a weakly prime, because it can be changed into another prime (68315941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34157960 + 34157961.

It is an arithmetic number, because the mean of its divisors is an integer number (34157961).

Almost surely, 2^68315921 is an apocalyptic number.

It is an amenable number.

68315921 is a deficient number, since it is larger than the sum of its proper divisors (1).

68315921 is an equidigital number, since it uses as much as digits as its factorization.

68315921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 68315921 is about 8265.3445784190. The cubic root of 68315921 is about 408.7966321370.

The spelling of 68315921 in words is "sixty-eight million, three hundred fifteen thousand, nine hundred twenty-one".