2121606 has 32 divisors (see below), whose sum is σ = 4773600. Its totient is φ = 698400.

The previous prime is 2121601. The next prime is 2121607. The reversal of 2121606 is 6061212.

It is a happy number.

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

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5260 + ... + 5648.

It is an arithmetic number, because the mean of its divisors is an integer number (149175).

2^2121606 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2121606, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2386800).

2121606 is an abundant number, since it is smaller than the sum of its proper divisors (2651994).

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

2121606 is a wasteful number, since it uses less digits than its factorization.

2121606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 495 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 2121606 is about 1456.5733761126. The cubic root of 2121606 is about 128.4955965526.

Adding to 2121606 its reverse (6061212), we get a palindrome (8182818).

The spelling of 2121606 in words is "two million, one hundred twenty-one thousand, six hundred six".