68121857 has 2 divisors, whose sum is σ = 68121858. Its totient is φ = 68121856.

The previous prime is 68121853. The next prime is 68121863. The reversal of 68121857 is 75812186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39488656 + 28633201 = 6284^2 + 5351^2 .

It is a cyclic number.

It is not a de Polignac number, because 68121857 - 2² = 68121853 is a prime.

It is a super-2 number, since 2×68121857² = 9281174802256898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 68121857.

It is not a weakly prime, because it can be changed into another prime (68121853) 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, 34060928 + 34060929.

It is an arithmetic number, because the mean of its divisors is an integer number (34060929).

Almost surely, 2^68121857 is an apocalyptic number.

It is an amenable number.

68121857 is a deficient number, since it is larger than the sum of its proper divisors (1).

68121857 is an equidigital number, since it uses as much as digits as its factorization.

68121857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26880, while the sum is 38.

The square root of 68121857 is about 8253.5966099634. The cubic root of 68121857 is about 408.4091775634.

The spelling of 68121857 in words is "sixty-eight million, one hundred twenty-one thousand, eight hundred fifty-seven".