55400440 has 64 divisors (see below), whose sum is σ = 130183200. Its totient is φ = 21192192.

The previous prime is 55400417. The next prime is 55400459. The reversal of 55400440 is 4400455.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188934 + ... + 189226.

Almost surely, 2^55400440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55400440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65091600).

55400440 is an abundant number, since it is smaller than the sum of its proper divisors (74782760).

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

55400440 is a wasteful number, since it uses less digits than its factorization.

55400440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 22.

The square root of 55400440 is about 7443.1471838195. The cubic root of 55400440 is about 381.2159571861.

Adding to 55400440 its reverse (4400455), we get a palindrome (59800895).

The spelling of 55400440 in words is "fifty-five million, four hundred thousand, four hundred forty".