68655581 has 2 divisors, whose sum is σ = 68655582. Its totient is φ = 68655580.

The previous prime is 68655553. The next prime is 68655589. The reversal of 68655581 is 18555686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42133081 + 26522500 = 6491^2 + 5150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68655581 is a prime.

It is a super-2 number, since 2×68655581² = 9427177604895122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68655589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34327790 + 34327791.

It is an arithmetic number, because the mean of its divisors is an integer number (34327791).

Almost surely, 2^68655581 is an apocalyptic number.

It is an amenable number.

68655581 is a deficient number, since it is larger than the sum of its proper divisors (1).

68655581 is an equidigital number, since it uses as much as digits as its factorization.

68655581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288000, while the sum is 44.

The square root of 68655581 is about 8285.8663397378. The cubic root of 68655581 is about 409.4730112120.

The spelling of 68655581 in words is "sixty-eight million, six hundred fifty-five thousand, five hundred eighty-one".