640242266 has 16 divisors (see below), whose sum is σ = 977453568. Its totient is φ = 314460000.

The previous prime is 640242247. The next prime is 640242299. The reversal of 640242266 is 662242046.

It is an unprimeable number.

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, 27911 + ... + 45381.

It is an arithmetic number, because the mean of its divisors is an integer number (61090848).

Almost surely, 2^640242266 is an apocalyptic number.

640242266 is a deficient number, since it is larger than the sum of its proper divisors (337211302).

640242266 is a wasteful number, since it uses less digits than its factorization.

640242266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17797.

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 640242266 is about 25303.0090305481. The cubic root of 640242266 is about 861.8826011022.

The spelling of 640242266 in words is "six hundred forty million, two hundred forty-two thousand, two hundred sixty-six".