68383981 has 2 divisors, whose sum is σ = 68383982. Its totient is φ = 68383980.

The previous prime is 68383967. The next prime is 68384027. The reversal of 68383981 is 18938386.

It is an a-pointer prime, because the next prime (68384027) can be obtained adding 68383981 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67798756 + 585225 = 8234^2 + 765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68383981 is a prime.

It is a super-2 number, since 2×68383981² = 9352737714816722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68383481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34191990 + 34191991.

It is an arithmetic number, because the mean of its divisors is an integer number (34191991).

Almost surely, 2^68383981 is an apocalyptic number.

It is an amenable number.

68383981 is a deficient number, since it is larger than the sum of its proper divisors (1).

68383981 is an equidigital number, since it uses as much as digits as its factorization.

68383981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 68383981 is about 8269.4607442082. The cubic root of 68383981 is about 408.9323421540.

The spelling of 68383981 in words is "sixty-eight million, three hundred eighty-three thousand, nine hundred eighty-one".