640251473862 has 128 divisors (see below), whose sum is σ = 1720455367680. Its totient is φ = 153401610240.

The previous prime is 640251473839. The next prime is 640251473879. The reversal of 640251473862 is 268374152046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8907138 + ... + 8978730.

It is an arithmetic number, because the mean of its divisors is an integer number (13441057560).

Almost surely, 2^640251473862 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640251473862, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (860227683840).

640251473862 is an abundant number, since it is smaller than the sum of its proper divisors (1080203893818).

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

640251473862 is a wasteful number, since it uses less digits than its factorization.

640251473862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73118.

The product of its (nonzero) digits is 1935360, while the sum is 48.

The spelling of 640251473862 in words is "six hundred forty billion, two hundred fifty-one million, four hundred seventy-three thousand, eight hundred sixty-two".