55561000 has 64 divisors (see below), whose sum is σ = 141860160. Its totient is φ = 20200000.

The previous prime is 55560991. The next prime is 55561001. The reversal of 55561000 is 16555.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (55561001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8475 + ... + 13525.

It is an arithmetic number, because the mean of its divisors is an integer number (2216565).

Almost surely, 2^55561000 is an apocalyptic number.

55561000 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 55561000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70930080).

55561000 is an abundant number, since it is smaller than the sum of its proper divisors (86299160).

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

55561000 is a wasteful number, since it uses less digits than its factorization.

55561000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5083 (or 5069 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 55561000 is about 7453.9251404881. The cubic root of 55561000 is about 381.5838784435.

Adding to 55561000 its reverse (16555), we get a palindrome (55577555).

It can be divided in two parts, 5556 and 1000, that added together give a palindrome (6556).

The spelling of 55561000 in words is "fifty-five million, five hundred sixty-one thousand".