640536783 has 8 divisors (see below), whose sum is σ = 868050096. Its totient is φ = 420024000.

The previous prime is 640536781. The next prime is 640536803. The reversal of 640536783 is 387635046.

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

It is not a de Polignac number, because 640536783 - 2¹ = 640536781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640536781) 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, 1749918 + ... + 1750283.

It is an arithmetic number, because the mean of its divisors is an integer number (108506262).

Almost surely, 2^640536783 is an apocalyptic number.

640536783 is a deficient number, since it is larger than the sum of its proper divisors (227513313).

640536783 is a wasteful number, since it uses less digits than its factorization.

640536783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3500265.

The product of its (nonzero) digits is 362880, while the sum is 42.

The square root of 640536783 is about 25308.8281633109. The cubic root of 640536783 is about 862.0147386688.

The spelling of 640536783 in words is "six hundred forty million, five hundred thirty-six thousand, seven hundred eighty-three".