2189904185728 has 128 divisors (see below), whose sum is σ = 5028687083520. Its totient is φ = 930510637056.

The previous prime is 2189904185687. The next prime is 2189904185747. The reversal of 2189904185728 is 8275814099812.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a self number, because there is not a number n which added to its sum of digits gives 2189904185728.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65114325 + ... + 65147947.

It is an arithmetic number, because the mean of its divisors is an integer number (39286617840).

Almost surely, 2^{2189904185728} is an apocalyptic number.

2189904185728 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 2189904185728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2514343541760).

2189904185728 is an abundant number, since it is smaller than the sum of its proper divisors (2838782897792).

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

2189904185728 is a wasteful number, since it uses less digits than its factorization.

2189904185728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34264 (or 34252 counting only the distinct ones).

The product of its (nonzero) digits is 23224320, while the sum is 64.

The spelling of 2189904185728 in words is "two trillion, one hundred eighty-nine billion, nine hundred four million, one hundred eighty-five thousand, seven hundred twenty-eight".