2091816 has 48 divisors (see below), whose sum is σ = 6002100. Its totient is φ = 655872.

The previous prime is 2091809. The next prime is 2091839. The reversal of 2091816 is 6181902.

It can be written as a sum of positive squares in 2 ways, for example, as 2090916 + 900 = 1446^2 + 30^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2091816.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 370 + ... + 2078.

2^2091816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2091816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3001050).

2091816 is an abundant number, since it is smaller than the sum of its proper divisors (3910284).

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

2091816 is a wasteful number, since it uses less digits than its factorization.

2091816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1738 (or 1731 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 2091816 is about 1446.3111698386. The cubic root of 2091816 is about 127.8913465972.

It can be divided in two parts, 209 and 1816, that added together give a square (2025 = 45²).

The spelling of 2091816 in words is "two million, ninety-one thousand, eight hundred sixteen".