20128889 has 8 divisors (see below), whose sum is σ = 22667520. Its totient is φ = 17708400.

The previous prime is 20128883. The next prime is 20128897. The reversal of 20128889 is 98882102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20128889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20128883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29174 + ... + 29855.

It is an arithmetic number, because the mean of its divisors is an integer number (2833440).

Almost surely, 2^20128889 is an apocalyptic number.

It is an amenable number.

20128889 is a deficient number, since it is larger than the sum of its proper divisors (2538631).

20128889 is a wasteful number, since it uses less digits than its factorization.

20128889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59071.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 20128889 is about 4486.5230412871. The cubic root of 20128889 is about 272.0236111640.

It can be divided in two parts, 2012 and 8889, that added together give a palindrome (10901).

The spelling of 20128889 in words is "twenty million, one hundred twenty-eight thousand, eight hundred eighty-nine".