640043702 has 16 divisors (see below), whose sum is σ = 984312000. Its totient is φ = 311952960.

The previous prime is 640043683. The next prime is 640043707. The reversal of 640043702 is 207340046.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640043707) 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, 124499 + ... + 129537.

It is an arithmetic number, because the mean of its divisors is an integer number (61519500).

Almost surely, 2^640043702 is an apocalyptic number.

640043702 is a deficient number, since it is larger than the sum of its proper divisors (344268298).

640043702 is a wasteful number, since it uses less digits than its factorization.

640043702 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6631.

The product of its (nonzero) digits is 4032, while the sum is 26.

The square root of 640043702 is about 25299.0850032170. The cubic root of 640043702 is about 861.7934907965.

Adding to 640043702 its reverse (207340046), we get a palindrome (847383748).

The spelling of 640043702 in words is "six hundred forty million, forty-three thousand, seven hundred two".