2181765 has 8 divisors (see below), whose sum is σ = 3490848. Its totient is φ = 1163600.

The previous prime is 2181737. The next prime is 2181833. The reversal of 2181765 is 5671812.

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

It is not a de Polignac number, because 2181765 - 2¹⁰ = 2180741 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72711 + ... + 72740.

It is an arithmetic number, because the mean of its divisors is an integer number (436356).

2^2181765 is an apocalyptic number.

It is an amenable number.

2181765 is a deficient number, since it is larger than the sum of its proper divisors (1309083).

2181765 is a wasteful number, since it uses less digits than its factorization.

2181765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145459.

The product of its digits is 3360, while the sum is 30.

The square root of 2181765 is about 1477.0798895117. The cubic root of 2181765 is about 129.6988096297.

The spelling of 2181765 in words is "two million, one hundred eighty-one thousand, seven hundred sixty-five".