68660513 has 2 divisors, whose sum is σ = 68660514. Its totient is φ = 68660512.

The previous prime is 68660503. The next prime is 68660519. The reversal of 68660513 is 31506686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61653904 + 7006609 = 7852^2 + 2647^2 .

It is a cyclic number.

It is not a de Polignac number, because 68660513 - 2¹² = 68656417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (68660519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34330256 + 34330257.

It is an arithmetic number, because the mean of its divisors is an integer number (34330257).

Almost surely, 2^68660513 is an apocalyptic number.

It is an amenable number.

68660513 is a deficient number, since it is larger than the sum of its proper divisors (1).

68660513 is an equidigital number, since it uses as much as digits as its factorization.

68660513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 68660513 is about 8286.1639496211. The cubic root of 68660513 is about 409.4828160597.

The spelling of 68660513 in words is "sixty-eight million, six hundred sixty thousand, five hundred thirteen".