2189743821 has 16 divisors (see below), whose sum is σ = 3246229120. Its totient is φ = 1458855360.

The previous prime is 2189743799. The next prime is 2189743823. The reversal of 2189743821 is 1283479812.

It is a happy number.

It is not a de Polignac number, because 2189743821 - 2⁷ = 2189743693 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2189743823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15381 + ... + 67941.

It is an arithmetic number, because the mean of its divisors is an integer number (202889320).

Almost surely, 2^2189743821 is an apocalyptic number.

It is an amenable number.

2189743821 is a deficient number, since it is larger than the sum of its proper divisors (1056485299).

2189743821 is a wasteful number, since it uses less digits than its factorization.

2189743821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54113 (or 54107 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 2189743821 is about 46794.6986420470. The cubic root of 2189743821 is about 1298.5672224498.

The spelling of 2189743821 in words is "two billion, one hundred eighty-nine million, seven hundred forty-three thousand, eight hundred twenty-one".