2189445840 has 120 divisors (see below), whose sum is σ = 7375905888. Its totient is φ = 582024960.

The previous prime is 2189445803. The next prime is 2189445859. The reversal of 2189445840 is 485449812.

2189445840 is a `hidden beast` number, since 21 + 8 + 9 + 44 + 584 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 233727 + ... + 242913.

Almost surely, 2^2189445840 is an apocalyptic number.

2189445840 is a gapful number since it is divisible by the number (20) 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 2189445840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3687952944).

2189445840 is an abundant number, since it is smaller than the sum of its proper divisors (5186460048).

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

2189445840 is a wasteful number, since it uses less digits than its factorization.

2189445840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9537 (or 9528 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The square root of 2189445840 is about 46791.5146153659. The cubic root of 2189445840 is about 1298.5083166379.

The spelling of 2189445840 in words is "two billion, one hundred eighty-nine million, four hundred forty-five thousand, eight hundred forty".