66563617 has 2 divisors, whose sum is σ = 66563618. Its totient is φ = 66563616.

The previous prime is 66563611. The next prime is 66563639. The reversal of 66563617 is 71636566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64256256 + 2307361 = 8016^2 + 1519^2 .

It is a cyclic number.

It is not a de Polignac number, because 66563617 - 2⁷ = 66563489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66563617.

It is not a weakly prime, because it can be changed into another prime (66563611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33281808 + 33281809.

It is an arithmetic number, because the mean of its divisors is an integer number (33281809).

Almost surely, 2^66563617 is an apocalyptic number.

It is an amenable number.

66563617 is a deficient number, since it is larger than the sum of its proper divisors (1).

66563617 is an equidigital number, since it uses as much as digits as its factorization.

66563617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 40.

The square root of 66563617 is about 8158.6528912560. The cubic root of 66563617 is about 405.2711023357.

The spelling of 66563617 in words is "sixty-six million, five hundred sixty-three thousand, six hundred seventeen".