2101605 has 32 divisors (see below), whose sum is σ = 3760128. Its totient is φ = 993600.

The previous prime is 2101553. The next prime is 2101607. The reversal of 2101605 is 5061012.

It is not a de Polignac number, because 2101605 - 2⁹ = 2101093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

2101605 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7620 + ... + 7890.

It is an arithmetic number, because the mean of its divisors is an integer number (117504).

2^2101605 is an apocalyptic number.

It is an amenable number.

2101605 is a deficient number, since it is larger than the sum of its proper divisors (1658523).

2101605 is a wasteful number, since it uses less digits than its factorization.

2101605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 2101605 is about 1449.6913464597. The cubic root of 2101605 is about 128.0905324696.

Adding to 2101605 its reverse (5061012), we get a palindrome (7162617).

The spelling of 2101605 in words is "two million, one hundred one thousand, six hundred five".