646613647 has 2 divisors, whose sum is σ = 646613648. Its totient is φ = 646613646.

The previous prime is 646613579. The next prime is 646613659. The reversal of 646613647 is 746316646.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646613647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646613447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323306823 + 323306824.

It is an arithmetic number, because the mean of its divisors is an integer number (323306824).

Almost surely, 2^646613647 is an apocalyptic number.

646613647 is a deficient number, since it is larger than the sum of its proper divisors (1).

646613647 is an equidigital number, since it uses as much as digits as its factorization.

646613647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 43.

The square root of 646613647 is about 25428.5989979786. The cubic root of 646613647 is about 864.7321821151.

The spelling of 646613647 in words is "six hundred forty-six million, six hundred thirteen thousand, six hundred forty-seven".