640661514 has 16 divisors (see below), whose sum is σ = 1281843360. Its totient is φ = 213467120.

The previous prime is 640661501. The next prime is 640661519. The reversal of 640661514 is 415166046.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (640661519) 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, 4644 + ... + 36095.

It is an arithmetic number, because the mean of its divisors is an integer number (80115210).

Almost surely, 2^640661514 is an apocalyptic number.

640661514 is an abundant number, since it is smaller than the sum of its proper divisors (641181846).

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

640661514 is a wasteful number, since it uses less digits than its factorization.

640661514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43365.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 640661514 is about 25311.2922230375. The cubic root of 640661514 is about 862.0706880875.

The spelling of 640661514 in words is "six hundred forty million, six hundred sixty-one thousand, five hundred fourteen".