55400400 has 180 divisors, whose sum is σ = 209882400. Its totient is φ = 13420800.

The previous prime is 55400369. The next prime is 55400407. The reversal of 55400400 is 400455.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55400407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 38901 + ... + 40299.

Almost surely, 2^55400400 is an apocalyptic number.

55400400 is a gapful number since it is divisible by the number (50) 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 55400400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104941200).

55400400 is an abundant number, since it is smaller than the sum of its proper divisors (154482000).

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

55400400 is a wasteful number, since it uses less digits than its factorization.

55400400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434 (or 1420 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 55400400 is about 7443.1444967836. The cubic root of 55400400 is about 381.2158654380.

Adding to 55400400 its reverse (400455), we get a palindrome (55800855).

Subtracting from 55400400 its reverse (400455), we obtain a palindrome (54999945).

The spelling of 55400400 in words is "fifty-five million, four hundred thousand, four hundred".