640251366 has 8 divisors (see below), whose sum is σ = 1280502744. Its totient is φ = 213417120.

The previous prime is 640251349. The next prime is 640251371. The reversal of 640251366 is 663152046.

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

640251366 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53354275 + ... + 53354286.

It is an arithmetic number, because the mean of its divisors is an integer number (160062843).

Almost surely, 2^640251366 is an apocalyptic number.

640251366 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640251366 is a wasteful number, since it uses less digits than its factorization.

640251366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106708566.

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 640251366 is about 25303.1888504196. The cubic root of 640251366 is about 861.8866845015.

The spelling of 640251366 in words is "six hundred forty million, two hundred fifty-one thousand, three hundred sixty-six".