68809561 has 2 divisors, whose sum is σ = 68809562. Its totient is φ = 68809560.

The previous prime is 68809519. The next prime is 68809613. The reversal of 68809561 is 16590886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68161536 + 648025 = 8256^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 68809561 - 2⁹ = 68809049 is a prime.

It is not a weakly prime, because it can be changed into another prime (68809501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34404780 + 34404781.

It is an arithmetic number, because the mean of its divisors is an integer number (34404781).

Almost surely, 2^68809561 is an apocalyptic number.

It is an amenable number.

68809561 is a deficient number, since it is larger than the sum of its proper divisors (1).

68809561 is an equidigital number, since it uses as much as digits as its factorization.

68809561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 68809561 is about 8295.1528617621. The cubic root of 68809561 is about 409.7789032000.

The spelling of 68809561 in words is "sixty-eight million, eight hundred nine thousand, five hundred sixty-one".