640436646630 has 64 divisors (see below), whose sum is σ = 1678081536000. Its totient is φ = 155136817920.

The previous prime is 640436646581. The next prime is 640436646659. The reversal of 640436646630 is 36646634046.

It is a self number, because there is not a number n which added to its sum of digits gives 640436646630.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 327430 + ... + 1178169.

It is an arithmetic number, because the mean of its divisors is an integer number (26220024000).

Almost surely, 2^640436646630 is an apocalyptic number.

640436646630 is an abundant number, since it is smaller than the sum of its proper divisors (1037644889370).

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

640436646630 is a wasteful number, since it uses less digits than its factorization.

640436646630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506909.

The product of its (nonzero) digits is 4478976, while the sum is 48.

The spelling of 640436646630 in words is "six hundred forty billion, four hundred thirty-six million, six hundred forty-six thousand, six hundred thirty".