2181838133 has 4 divisors (see below), whose sum is σ = 2194903200. Its totient is φ = 2168773068.

The previous prime is 2181838129. The next prime is 2181838159. The reversal of 2181838133 is 3318381812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2181838133 - 2² = 2181838129 is a prime.

It is a super-2 number, since 2×2181838133² = 9520835277225851378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181838433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6532283 + ... + 6532616.

It is an arithmetic number, because the mean of its divisors is an integer number (548725800).

Almost surely, 2^2181838133 is an apocalyptic number.

It is an amenable number.

2181838133 is a deficient number, since it is larger than the sum of its proper divisors (13065067).

2181838133 is a wasteful number, since it uses less digits than its factorization.

2181838133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13065066.

The product of its digits is 27648, while the sum is 38.

The square root of 2181838133 is about 46710.1502138454. The cubic root of 2181838133 is about 1297.0025878619.

The spelling of 2181838133 in words is "two billion, one hundred eighty-one million, eight hundred thirty-eight thousand, one hundred thirty-three".