640293378 has 16 divisors (see below), whose sum is σ = 1324745280. Its totient is φ = 206071376.

The previous prime is 640293377. The next prime is 640293413. The reversal of 640293378 is 873392046.

It is not an unprimeable number, because it can be changed into a prime (640293377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1839750 + ... + 1840097.

It is an arithmetic number, because the mean of its divisors is an integer number (82796580).

Almost surely, 2^640293378 is an apocalyptic number.

640293378 is an abundant number, since it is smaller than the sum of its proper divisors (684451902).

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

640293378 is a wasteful number, since it uses less digits than its factorization.

640293378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3679881.

The product of its (nonzero) digits is 217728, while the sum is 42.

The square root of 640293378 is about 25304.0190088452. The cubic root of 640293378 is about 861.9055358430.

The spelling of 640293378 in words is "six hundred forty million, two hundred ninety-three thousand, three hundred seventy-eight".