644342232 has 32 divisors (see below), whose sum is σ = 1612497600. Its totient is φ = 214561824.

The previous prime is 644342227. The next prime is 644342243. The reversal of 644342232 is 232243446.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 644342232.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11283 + ... + 37629.

It is an arithmetic number, because the mean of its divisors is an integer number (50390550).

Almost surely, 2^644342232 is an apocalyptic number.

It is an amenable number.

644342232 is an abundant number, since it is smaller than the sum of its proper divisors (968155368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644342232 is a wasteful number, since it uses less digits than its factorization.

644342232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27375 (or 27371 counting only the distinct ones).

The product of its digits is 27648, while the sum is 30.

The square root of 644342232 is about 25383.8971003272. The cubic root of 644342232 is about 863.7184546469.

Adding to 644342232 its reverse (232243446), we get a palindrome (876585678).

It can be divided in two parts, 64434 and 2232, that added together give a palindrome (66666).

The spelling of 644342232 in words is "six hundred forty-four million, three hundred forty-two thousand, two hundred thirty-two".