640069188 has 72 divisors (see below), whose sum is σ = 1728084960. Its totient is φ = 183744000.

The previous prime is 640069153. The next prime is 640069201. The reversal of 640069188 is 881960046.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 15988 + ... + 39188.

It is an arithmetic number, because the mean of its divisors is an integer number (24001180).

Almost surely, 2^640069188 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 640069188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (864042480).

640069188 is an abundant number, since it is smaller than the sum of its proper divisors (1088015772).

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

640069188 is a wasteful number, since it uses less digits than its factorization.

640069188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23249 (or 23236 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 640069188 is about 25299.5886923088. The cubic root of 640069188 is about 861.8049292745.

The spelling of 640069188 in words is "six hundred forty million, sixty-nine thousand, one hundred eighty-eight".