2181901 has 8 divisors (see below), whose sum is σ = 2246400. Its totient is φ = 2118480.

The previous prime is 2181889. The next prime is 2181919. The reversal of 2181901 is 1091812.

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 2181901 - 2⁵ = 2181869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181601) 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, 5415 + ... + 5803.

It is an arithmetic number, because the mean of its divisors is an integer number (280800).

2^2181901 is an apocalyptic number.

It is an amenable number.

2181901 is a deficient number, since it is larger than the sum of its proper divisors (64499).

2181901 is an equidigital number, since it uses as much as digits as its factorization.

2181901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 2181901 is about 1477.1259255730. The cubic root of 2181901 is about 129.7015044924.

The spelling of 2181901 in words is "two million, one hundred eighty-one thousand, nine hundred one".