640387446 has 32 divisors (see below), whose sum is σ = 1336795488. Its totient is φ = 204322560.

The previous prime is 640387441. The next prime is 640387469. The reversal of 640387446 is 644783046.

640387446 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 640387398 and 640387407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640387441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11521 + ... + 37596.

It is an arithmetic number, because the mean of its divisors is an integer number (41774859).

Almost surely, 2^640387446 is an apocalyptic number.

640387446 is an abundant number, since it is smaller than the sum of its proper divisors (696408042).

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

640387446 is a wasteful number, since it uses less digits than its factorization.

640387446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49216.

The product of its (nonzero) digits is 387072, while the sum is 42.

The square root of 640387446 is about 25305.8776966933. The cubic root of 640387446 is about 861.9477424119.

The spelling of 640387446 in words is "six hundred forty million, three hundred eighty-seven thousand, four hundred forty-six".