2091660 has 48 divisors (see below), whose sum is σ = 5951232. Its totient is φ = 548800.

The previous prime is 2091659. The next prime is 2091667. The reversal of 2091660 is 661902.

It is a self number, because there is not a number n which added to its sum of digits gives 2091660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2091667) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4015 + ... + 4505.

It is an arithmetic number, because the mean of its divisors is an integer number (123984).

2^2091660 is an apocalyptic number.

2091660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2091660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2975616).

2091660 is an abundant number, since it is smaller than the sum of its proper divisors (3859572).

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

2091660 is a wasteful number, since it uses less digits than its factorization.

2091660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574 (or 572 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 2091660 is about 1446.2572385299. The cubic root of 2091660 is about 127.8881672950. Note that the first 3 decimals are identical.

The spelling of 2091660 in words is "two million, ninety-one thousand, six hundred sixty".