640039701 has 8 divisors (see below), whose sum is σ = 975298624. Its totient is φ = 365736960.

The previous prime is 640039651. The next prime is 640039717. The reversal of 640039701 is 107930046.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640039701 - 2⁶ = 640039637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640034701) 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, 15239020 + ... + 15239061.

It is an arithmetic number, because the mean of its divisors is an integer number (121912328).

Almost surely, 2^640039701 is an apocalyptic number.

It is an amenable number.

640039701 is a deficient number, since it is larger than the sum of its proper divisors (335258923).

640039701 is a wasteful number, since it uses less digits than its factorization.

640039701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30478091.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 640039701 is about 25299.0059290874. The cubic root of 640039701 is about 861.7916950634.

Adding to 640039701 its reverse (107930046), we get a palindrome (747969747).

The spelling of 640039701 in words is "six hundred forty million, thirty-nine thousand, seven hundred one".