640265472 has 360 divisors, whose sum is σ = 2386181952. Its totient is φ = 165888000.

The previous prime is 640265453. The next prime is 640265489. The reversal of 640265472 is 274562046.

640265472 is a `hidden beast` number, since 640 + 2 + 6 + 5 + 4 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1596472 + ... + 1596872.

Almost surely, 2^640265472 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 640265472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1193090976).

640265472 is an abundant number, since it is smaller than the sum of its proper divisors (1745916480).

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

640265472 is a wasteful number, since it uses less digits than its factorization.

640265472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The square root of 640265472 is about 25303.4675884551. The cubic root of 640265472 is about 861.8930141427.

The spelling of 640265472 in words is "six hundred forty million, two hundred sixty-five thousand, four hundred seventy-two".