68581309 has 2 divisors, whose sum is σ = 68581310. Its totient is φ = 68581308.

The previous prime is 68581291. The next prime is 68581327. The reversal of 68581309 is 90318586.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (68581291) and next prime (68581327).

It can be written as a sum of positive squares in only one way, i.e., 57836025 + 10745284 = 7605^2 + 3278^2 .

It is a cyclic number.

It is not a de Polignac number, because 68581309 - 2⁷ = 68581181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68581339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34290654 + 34290655.

It is an arithmetic number, because the mean of its divisors is an integer number (34290655).

Almost surely, 2^68581309 is an apocalyptic number.

It is an amenable number.

68581309 is a deficient number, since it is larger than the sum of its proper divisors (1).

68581309 is an equidigital number, since it uses as much as digits as its factorization.

68581309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 68581309 is about 8281.3832781728. The cubic root of 68581309 is about 409.3253011866.

The spelling of 68581309 in words is "sixty-eight million, five hundred eighty-one thousand, three hundred nine".