634440 has 64 divisors (see below), whose sum is σ = 2021760. Its totient is φ = 158720.

The previous prime is 634421. The next prime is 634441. The reversal of 634440 is 44436.

It is a super-2 number, since 2×634440² = 805028227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634441) by changing a digit.

634440 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1885 + ... + 2195.

It is an arithmetic number, because the mean of its divisors is an integer number (31590).

2⁶³⁴⁴⁴⁰ is an apocalyptic number.

634440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 634440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1010880).

634440 is an abundant number, since it is smaller than the sum of its proper divisors (1387320).

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

634440 is a wasteful number, since it uses less digits than its factorization.

634440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 634440 is about 796.5174197718. The cubic root of 634440 is about 85.9271060708.

Adding to 634440 its reverse (44436), we get a palindrome (678876).

The spelling of 634440 in words is "six hundred thirty-four thousand, four hundred forty".