55111232220 has 96 divisors (see below), whose sum is σ = 168496263936. Its totient is φ = 13347878400.

The previous prime is 55111232171. The next prime is 55111232261. The reversal of 55111232220 is 2223211155.

It is a super-2 number, since 2×55111232220² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 681792 + ... + 758328.

It is an arithmetic number, because the mean of its divisors is an integer number (1755169416).

Almost surely, 2^55111232220 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 55111232220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84248131968).

55111232220 is an abundant number, since it is smaller than the sum of its proper divisors (113385031716).

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

55111232220 is a wasteful number, since it uses less digits than its factorization.

55111232220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77651 (or 77649 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 55111232220 its reverse (2223211155), we get a palindrome (57334443375).

The spelling of 55111232220 in words is "fifty-five billion, one hundred eleven million, two hundred thirty-two thousand, two hundred twenty".