640347503 has 4 divisors (see below), whose sum is σ = 640579728. Its totient is φ = 640115280.

The previous prime is 640347497. The next prime is 640347511. The reversal of 640347503 is 305743046.

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

It is a cyclic number.

It is not a de Polignac number, because 640347503 - 2⁸ = 640347247 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640347503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640347583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111926 + ... + 117507.

It is an arithmetic number, because the mean of its divisors is an integer number (160144932).

Almost surely, 2^640347503 is an apocalyptic number.

640347503 is a deficient number, since it is larger than the sum of its proper divisors (232225).

640347503 is a wasteful number, since it uses less digits than its factorization.

640347503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232224.

The product of its (nonzero) digits is 30240, while the sum is 32.

The square root of 640347503 is about 25305.0884803828. The cubic root of 640347503 is about 861.9298212327.

The spelling of 640347503 in words is "six hundred forty million, three hundred forty-seven thousand, five hundred three".