68632981 has 2 divisors, whose sum is σ = 68632982. Its totient is φ = 68632980.

The previous prime is 68632957. The next prime is 68632987. The reversal of 68632981 is 18923686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40436881 + 28196100 = 6359^2 + 5310^2 .

It is a cyclic number.

It is not a de Polignac number, because 68632981 - 2⁹ = 68632469 is a prime.

It is a super-2 number, since 2×68632981² = 9420972161892722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68632987) 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, 34316490 + 34316491.

It is an arithmetic number, because the mean of its divisors is an integer number (34316491).

Almost surely, 2^68632981 is an apocalyptic number.

It is an amenable number.

68632981 is a deficient number, since it is larger than the sum of its proper divisors (1).

68632981 is an equidigital number, since it uses as much as digits as its factorization.

68632981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 43.

The square root of 68632981 is about 8284.5024594118. The cubic root of 68632981 is about 409.4280762603.

The spelling of 68632981 in words is "sixty-eight million, six hundred thirty-two thousand, nine hundred eighty-one".