55021020 has 96 divisors (see below), whose sum is σ = 159667200. Its totient is φ = 14148864.

The previous prime is 55021009. The next prime is 55021039. The reversal of 55021020 is 2012055.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 307291 + ... + 307469.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^55021020 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 55021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79833600).

55021020 is an abundant number, since it is smaller than the sum of its proper divisors (104646180).

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

55021020 is a wasteful number, since it uses less digits than its factorization.

55021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 55021020 is about 7417.6155198285. The cubic root of 55021020 is about 380.3436872151.

Adding to 55021020 its reverse (2012055), we get a palindrome (57033075).

The spelling of 55021020 in words is "fifty-five million, twenty-one thousand, twenty".