2181673 has 8 divisors (see below), whose sum is σ = 2362248. Its totient is φ = 2002944.

The previous prime is 2181671. The next prime is 2181689. The reversal of 2181673 is 3761812.

It can be written as a sum of positive squares in 4 ways, for example, as 310249 + 1871424 = 557^2 + 1368^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2181673 - 2¹ = 2181671 is a prime.

It is an Ulam number.

It is a Duffinian number.

2181673 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2181671) 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, 3015 + ... + 3667.

It is an arithmetic number, because the mean of its divisors is an integer number (295281).

2^2181673 is an apocalyptic number.

It is an amenable number.

2181673 is a deficient number, since it is larger than the sum of its proper divisors (180575).

2181673 is a wasteful number, since it uses less digits than its factorization.

2181673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923.

The product of its digits is 2016, while the sum is 28.

The square root of 2181673 is about 1477.0487466567. The cubic root of 2181673 is about 129.6969865708.

It can be divided in two parts, 218 and 1673, that added together give a triangular number (1891 = T₆₁).

The spelling of 2181673 in words is "two million, one hundred eighty-one thousand, six hundred seventy-three".