2181006 has 20 divisors (see below), whose sum is σ = 4887432. Its totient is φ = 726948.

The previous prime is 2180999. The next prime is 2181007. The reversal of 2181006 is 6001812.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 2181006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181007) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 6570 + ... + 6893.

2^2181006 is an apocalyptic number.

2181006 is an abundant number, since it is smaller than the sum of its proper divisors (2706426).

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

2181006 is a wasteful number, since it uses less digits than its factorization.

2181006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13477 (or 13468 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 2181006 is about 1476.8229413169. The cubic root of 2181006 is about 129.6837678609.

Adding to 2181006 its reverse (6001812), we get a palindrome (8182818).

The spelling of 2181006 in words is "two million, one hundred eighty-one thousand, six".