68771561 has 2 divisors, whose sum is σ = 68771562. Its totient is φ = 68771560.

The previous prime is 68771551. The next prime is 68771629. The reversal of 68771561 is 16517786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68475625 + 295936 = 8275^2 + 544^2 .

It is a cyclic number.

It is not a de Polignac number, because 68771561 - 2¹⁴ = 68755177 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (68771531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34385780 + 34385781.

It is an arithmetic number, because the mean of its divisors is an integer number (34385781).

Almost surely, 2^68771561 is an apocalyptic number.

It is an amenable number.

68771561 is a deficient number, since it is larger than the sum of its proper divisors (1).

68771561 is an equidigital number, since it uses as much as digits as its factorization.

68771561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 41.

The square root of 68771561 is about 8292.8620511859. The cubic root of 68771561 is about 409.7034560022.

The spelling of 68771561 in words is "sixty-eight million, seven hundred seventy-one thousand, five hundred sixty-one".