19805128 has 32 divisors (see below), whose sum is σ = 42960960. Its totient is φ = 8383680.

The previous prime is 19805117. The next prime is 19805141. The reversal of 19805128 is 82150891.

It is a junction number, because it is equal to n+sod(n) for n = 19805093 and 19805102.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2518 + ... + 6778.

It is an arithmetic number, because the mean of its divisors is an integer number (1342530).

Almost surely, 2^19805128 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 19805128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21480480).

19805128 is an abundant number, since it is smaller than the sum of its proper divisors (23155832).

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

19805128 is a wasteful number, since it uses less digits than its factorization.

19805128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4357 (or 4353 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 19805128 is about 4450.2952711028. The cubic root of 19805128 is about 270.5572760680.

The spelling of 19805128 in words is "nineteen million, eight hundred five thousand, one hundred twenty-eight".