640785446 has 24 divisors (see below), whose sum is σ = 1123814736. Its totient is φ = 273220080.

The previous prime is 640785367. The next prime is 640785449. The reversal of 640785446 is 644587046.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 640785397 and 640785406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640785449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2711 + ... + 35901.

It is an arithmetic number, because the mean of its divisors is an integer number (46825614).

Almost surely, 2^640785446 is an apocalyptic number.

640785446 is a deficient number, since it is larger than the sum of its proper divisors (483029290).

640785446 is a wasteful number, since it uses less digits than its factorization.

640785446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33404 (or 33397 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 44.

The square root of 640785446 is about 25313.7402609729. The cubic root of 640785446 is about 862.1262719145.

The spelling of 640785446 in words is "six hundred forty million, seven hundred eighty-five thousand, four hundred forty-six".