68642381 has 2 divisors, whose sum is σ = 68642382. Its totient is φ = 68642380.

The previous prime is 68642377. The next prime is 68642443. The reversal of 68642381 is 18324686.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68641225 + 1156 = 8285^2 + 34^2 .

It is a cyclic number.

It is not a de Polignac number, because 68642381 - 2² = 68642377 is a prime.

It is a super-2 number, since 2×68642381² = 9423552938698322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68642081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34321190 + 34321191.

It is an arithmetic number, because the mean of its divisors is an integer number (34321191).

Almost surely, 2^68642381 is an apocalyptic number.

It is an amenable number.

68642381 is a deficient number, since it is larger than the sum of its proper divisors (1).

68642381 is an equidigital number, since it uses as much as digits as its factorization.

68642381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 38.

The square root of 68642381 is about 8285.0697643412. The cubic root of 68642381 is about 409.4467672170.

The spelling of 68642381 in words is "sixty-eight million, six hundred forty-two thousand, three hundred eighty-one".