634428918 has 48 divisors (see below), whose sum is σ = 1437976800. Its totient is φ = 201772032.

The previous prime is 634428913. The next prime is 634428929. The reversal of 634428918 is 819824436.

It is a happy number.

634428918 is a `hidden beast` number, since 634 + 4 + 2 + 8 + 9 + 1 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634428913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 184180 + ... + 187592.

It is an arithmetic number, because the mean of its divisors is an integer number (29957850).

Almost surely, 2^634428918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 634428918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (718988400).

634428918 is an abundant number, since it is smaller than the sum of its proper divisors (803547882).

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

634428918 is a wasteful number, since it uses less digits than its factorization.

634428918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3893 (or 3890 counting only the distinct ones).

The product of its digits is 331776, while the sum is 45.

The square root of 634428918 is about 25187.8724389338. The cubic root of 634428918 is about 859.2660576091.

The spelling of 634428918 in words is "six hundred thirty-four million, four hundred twenty-eight thousand, nine hundred eighteen".