640192278 has 64 divisors (see below), whose sum is σ = 1440799488. Its totient is φ = 187931520.

The previous prime is 640192249. The next prime is 640192283. The reversal of 640192278 is 872291046.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 773701 + ... + 774527.

It is an arithmetic number, because the mean of its divisors is an integer number (22512492).

Almost surely, 2^640192278 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640192278, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (720399744).

640192278 is an abundant number, since it is smaller than the sum of its proper divisors (800607210).

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

640192278 is a wasteful number, since it uses less digits than its factorization.

640192278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 640192278 is about 25302.0212236098. The cubic root of 640192278 is about 861.8601695368.

The spelling of 640192278 in words is "six hundred forty million, one hundred ninety-two thousand, two hundred seventy-eight".