640251612 has 288 divisors, whose sum is σ = 2206364160. Its totient is φ = 151165440.

The previous prime is 640251581. The next prime is 640251617. The reversal of 640251612 is 216152046.

640251612 is a `hidden beast` number, since 6 + 40 + 2 + 5 + 1 + 612 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640251617) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3927843 + ... + 3928005.

Almost surely, 2^640251612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640251612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1103182080).

640251612 is an abundant number, since it is smaller than the sum of its proper divisors (1566112548).

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

640251612 is a wasteful number, since it uses less digits than its factorization.

640251612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 640251612 is about 25303.1937114665. The cubic root of 640251612 is about 861.8867948874.

It can be divided in two parts, 640 and 251612, that added together give a palindrome (252252).

The spelling of 640251612 in words is "six hundred forty million, two hundred fifty-one thousand, six hundred twelve".