55000820 has 192 divisors, whose sum is σ = 154828800. Its totient is φ = 15966720.

The previous prime is 55000811. The next prime is 55000871. The reversal of 55000820 is 2800055.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 55000792 and 55000801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1774205 + ... + 1774235.

It is an arithmetic number, because the mean of its divisors is an integer number (806400).

Almost surely, 2^55000820 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 55000820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77414400).

55000820 is an abundant number, since it is smaller than the sum of its proper divisors (99827980).

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

55000820 is a wasteful number, since it uses less digits than its factorization.

55000820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 55000820 is about 7416.2537712783. The cubic root of 55000820 is about 380.2971360189.

Adding to 55000820 its reverse (2800055), we get a palindrome (57800875).

The spelling of 55000820 in words is "fifty-five million, eight hundred twenty", and thus it is an aban number.