20533128 has 128 divisors (see below), whose sum is σ = 65802240. Its totient is φ = 5184000.

The previous prime is 20533109. The next prime is 20533133. The reversal of 20533128 is 82133502.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 20533098 and 20533107.

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, 75633 + ... + 75903.

It is an arithmetic number, because the mean of its divisors is an integer number (514080).

Almost surely, 2^20533128 is an apocalyptic number.

20533128 is a gapful number since it is divisible by the number (28) 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 20533128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32901120).

20533128 is an abundant number, since it is smaller than the sum of its proper divisors (45269112).

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

20533128 is a wasteful number, since it uses less digits than its factorization.

20533128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 20533128 is about 4531.3494678738. The cubic root of 20533128 is about 273.8325294838.

It can be divided in two parts, 205 and 33128, that added together give a palindrome (33333).

The spelling of 20533128 in words is "twenty million, five hundred thirty-three thousand, one hundred twenty-eight".