646620266 has 16 divisors (see below), whose sum is σ = 1014733440. Its totient is φ = 308711520.

The previous prime is 646620263. The next prime is 646620277. The reversal of 646620266 is 662026646.

It is not an unprimeable number, because it can be changed into a prime (646620263) 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, 80036 + ... + 87743.

It is an arithmetic number, because the mean of its divisors is an integer number (63420840).

Almost surely, 2^646620266 is an apocalyptic number.

646620266 is a deficient number, since it is larger than the sum of its proper divisors (368113174).

646620266 is a wasteful number, since it uses less digits than its factorization.

646620266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167869.

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 646620266 is about 25428.7291463809. The cubic root of 646620266 is about 864.7351326883.

The spelling of 646620266 in words is "six hundred forty-six million, six hundred twenty thousand, two hundred sixty-six".