55128220 has 48 divisors (see below), whose sum is σ = 132753600. Its totient is φ = 18837504.

The previous prime is 55128211. The next prime is 55128221. The reversal of 55128220 is 2282155.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55128221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62422 + ... + 63298.

It is an arithmetic number, because the mean of its divisors is an integer number (2765700).

Almost surely, 2^55128220 is an apocalyptic number.

It is an amenable number.

55128220 is an abundant number, since it is smaller than the sum of its proper divisors (77625380).

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

55128220 is a wasteful number, since it uses less digits than its factorization.

55128220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 55128220 is about 7424.8380453718. The cubic root of 55128220 is about 380.5905407026.

The spelling of 55128220 in words is "fifty-five million, one hundred twenty-eight thousand, two hundred twenty".