20890128 has 80 divisors (see below), whose sum is σ = 62535680. Its totient is φ = 5885568.

The previous prime is 20890099. The next prime is 20890183. The reversal of 20890128 is 82109802.

It is a junction number, because it is equal to n+sod(n) for n = 20890095 and 20890104.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26151 + ... + 26937.

It is an arithmetic number, because the mean of its divisors is an integer number (781696).

Almost surely, 2^20890128 is an apocalyptic number.

20890128 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 20890128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31267840).

20890128 is an abundant number, since it is smaller than the sum of its proper divisors (41645552).

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

20890128 is a wasteful number, since it uses less digits than its factorization.

20890128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884 (or 878 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 20890128 is about 4570.5719554559. The cubic root of 20890128 is about 275.4104196774.

The spelling of 20890128 in words is "twenty million, eight hundred ninety thousand, one hundred twenty-eight".