68929921 has 2 divisors, whose sum is σ = 68929922. Its totient is φ = 68929920.

The previous prime is 68929907. The next prime is 68929963. The reversal of 68929921 is 12992986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54184321 + 14745600 = 7361^2 + 3840^2 .

It is a cyclic number.

It is not a de Polignac number, because 68929921 - 2⁷ = 68929793 is a prime.

It is not a weakly prime, because it can be changed into another prime (68929901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34464960 + 34464961.

It is an arithmetic number, because the mean of its divisors is an integer number (34464961).

Almost surely, 2^68929921 is an apocalyptic number.

It is an amenable number.

68929921 is a deficient number, since it is larger than the sum of its proper divisors (1).

68929921 is an equidigital number, since it uses as much as digits as its factorization.

68929921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 46.

The square root of 68929921 is about 8302.4045312187. The cubic root of 68929921 is about 410.0176891040.

The spelling of 68929921 in words is "sixty-eight million, nine hundred twenty-nine thousand, nine hundred twenty-one".