68545809 has 18 divisors (see below), whose sum is σ = 101661378. Its totient is φ = 44479200.

The previous prime is 68545781. The next prime is 68545817. The reversal of 68545809 is 90854586.

68545809 is a `hidden beast` number, since 68 + 5 + 4 + 580 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 41796225 + 26749584 = 6465^2 + 5172^2 .

It is not a de Polignac number, because 68545809 - 2⁹ = 68545297 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68545109) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 158824 + ... + 159254.

Almost surely, 2^68545809 is an apocalyptic number.

It is an amenable number.

68545809 is a deficient number, since it is larger than the sum of its proper divisors (33115569).

68545809 is an equidigital number, since it uses as much as digits as its factorization.

68545809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The square root of 68545809 is about 8279.2396390007. The cubic root of 68545809 is about 409.2546621336.

The spelling of 68545809 in words is "sixty-eight million, five hundred forty-five thousand, eight hundred nine".