640748234 has 16 divisors (see below), whose sum is σ = 1098750336. Its totient is φ = 274525200.

The previous prime is 640748197. The next prime is 640748239. The reversal of 640748234 is 432847046.

It is not an unprimeable number, because it can be changed into a prime (640748239) 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, 89819 + ... + 96689.

It is an arithmetic number, because the mean of its divisors is an integer number (68671896).

Almost surely, 2^640748234 is an apocalyptic number.

640748234 is a deficient number, since it is larger than the sum of its proper divisors (458002102).

640748234 is a wasteful number, since it uses less digits than its factorization.

640748234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13541.

The product of its (nonzero) digits is 129024, while the sum is 38.

The square root of 640748234 is about 25313.0052344640. The cubic root of 640748234 is about 862.1095829879.

The spelling of 640748234 in words is "six hundred forty million, seven hundred forty-eight thousand, two hundred thirty-four".