640436432064 has 224 divisors, whose sum is σ = 2054946969600. Its totient is φ = 173364019200.

The previous prime is 640436432047. The next prime is 640436432099. The reversal of 640436432064 is 460234634046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474912 + ... + 1227360.

It is an arithmetic number, because the mean of its divisors is an integer number (9173870400).

Almost surely, 2^640436432064 is an apocalyptic number.

640436432064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640436432064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1027473484800).

640436432064 is an abundant number, since it is smaller than the sum of its proper divisors (1414510537536).

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

640436432064 is a wasteful number, since it uses less digits than its factorization.

640436432064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752519 (or 752509 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 42.

The spelling of 640436432064 in words is "six hundred forty billion, four hundred thirty-six million, four hundred thirty-two thousand, sixty-four".