68644517 has 2 divisors, whose sum is σ = 68644518. Its totient is φ = 68644516.

The previous prime is 68644507. The next prime is 68644519. The reversal of 68644517 is 71544686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38328481 + 30316036 = 6191^2 + 5506^2 .

It is a cyclic number.

It is not a de Polignac number, because 68644517 - 2¹² = 68640421 is a prime.

Together with 68644519, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68644519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34322258 + 34322259.

It is an arithmetic number, because the mean of its divisors is an integer number (34322259).

Almost surely, 2^68644517 is an apocalyptic number.

It is an amenable number.

68644517 is a deficient number, since it is larger than the sum of its proper divisors (1).

68644517 is an equidigital number, since it uses as much as digits as its factorization.

68644517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 41.

The square root of 68644517 is about 8285.1986699173. The cubic root of 68644517 is about 409.4510142007.

The spelling of 68644517 in words is "sixty-eight million, six hundred forty-four thousand, five hundred seventeen".