20445128 has 24 divisors (see below), whose sum is σ = 42138390. Its totient is φ = 9292800.

The previous prime is 20445109. The next prime is 20445143. The reversal of 20445128 is 82154402.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15507844 + 4937284 = 3938^2 + 2222^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20445097 and 20445106.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9593 + ... + 11528.

Almost surely, 2^20445128 is an apocalyptic number.

It is an amenable number.

20445128 is an abundant number, since it is smaller than the sum of its proper divisors (21693262).

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

20445128 is a wasteful number, since it uses less digits than its factorization.

20445128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21149 (or 21134 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 20445128 is about 4521.6289100279. The cubic root of 20445128 is about 273.4407760565.

The spelling of 20445128 in words is "twenty million, four hundred forty-five thousand, one hundred twenty-eight".