2191885 has 4 divisors (see below), whose sum is σ = 2630268. Its totient is φ = 1753504.

The previous prime is 2191883. The next prime is 2191949. The reversal of 2191885 is 5881912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1572516 + 619369 = 1254^2 + 787^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191885 - 2¹ = 2191883 is a prime.

It is a Duffinian number.

2191885 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2191885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191883) 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, 219184 + ... + 219193.

It is an arithmetic number, because the mean of its divisors is an integer number (657567).

2^2191885 is an apocalyptic number.

It is an amenable number.

2191885 is a deficient number, since it is larger than the sum of its proper divisors (438383).

2191885 is an equidigital number, since it uses as much as digits as its factorization.

2191885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438382.

The product of its digits is 5760, while the sum is 34.

The square root of 2191885 is about 1480.5016041869. The cubic root of 2191885 is about 129.8990340300.

It can be divided in two parts, 219188 and 5, that multiplied together give a triangular number (1095940 = T₁₄₈₀).

The spelling of 2191885 in words is "two million, one hundred ninety-one thousand, eight hundred eighty-five".