646613651 has 8 divisors (see below), whose sum is σ = 675035424. Its totient is φ = 618217600.

The previous prime is 646613647. The next prime is 646613659. The reversal of 646613651 is 156316646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646613651 - 2² = 646613647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646613659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59405 + ... + 69441.

It is an arithmetic number, because the mean of its divisors is an integer number (84379428).

Almost surely, 2^646613651 is an apocalyptic number.

646613651 is a deficient number, since it is larger than the sum of its proper divisors (28421773).

646613651 is a wasteful number, since it uses less digits than its factorization.

646613651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12861.

The product of its digits is 77760, while the sum is 38.

The square root of 646613651 is about 25428.5990766302. The cubic root of 646613651 is about 864.7321838982.

The spelling of 646613651 in words is "six hundred forty-six million, six hundred thirteen thousand, six hundred fifty-one".