640195814 has 4 divisors (see below), whose sum is σ = 960293724. Its totient is φ = 320097906.

The previous prime is 640195813. The next prime is 640195819. The reversal of 640195814 is 418591046.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640195811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160048952 + ... + 160048955.

It is an arithmetic number, because the mean of its divisors is an integer number (240073431).

Almost surely, 2^640195814 is an apocalyptic number.

640195814 is a deficient number, since it is larger than the sum of its proper divisors (320097910).

640195814 is a wasteful number, since it uses less digits than its factorization.

640195814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320097909.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 640195814 is about 25302.0910993538. The cubic root of 640195814 is about 861.8617563163.

The spelling of 640195814 in words is "six hundred forty million, one hundred ninety-five thousand, eight hundred fourteen".