640740583 has 8 divisors (see below), whose sum is σ = 734864768. Its totient is φ = 547263864.

The previous prime is 640740571. The next prime is 640740589. The reversal of 640740583 is 385047046.

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

It is not a de Polignac number, because 640740583 - 2⁹ = 640740071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640740589) 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, 159741 + ... + 163702.

It is an arithmetic number, because the mean of its divisors is an integer number (91858096).

Almost surely, 2^640740583 is an apocalyptic number.

640740583 is a deficient number, since it is larger than the sum of its proper divisors (94124185).

640740583 is a wasteful number, since it uses less digits than its factorization.

640740583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323733.

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 640740583 is about 25312.8541061651. The cubic root of 640740583 is about 862.1061515690.

The spelling of 640740583 in words is "six hundred forty million, seven hundred forty thousand, five hundred eighty-three".