2100905 has 8 divisors (see below), whose sum is σ = 2608200. Its totient is φ = 1622656.

The previous prime is 2100899. The next prime is 2100913. The reversal of 2100905 is 5090012.

It can be written as a sum of positive squares in 4 ways, for example, as 38809 + 2062096 = 197^2 + 1436^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2100905 - 2⁶ = 2100841 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7100 + ... + 7389.

It is an arithmetic number, because the mean of its divisors is an integer number (326025).

2^2100905 is an apocalyptic number.

It is an amenable number.

2100905 is a deficient number, since it is larger than the sum of its proper divisors (507295).

2100905 is a wasteful number, since it uses less digits than its factorization.

2100905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14523.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 2100905 is about 1449.4498956501. The cubic root of 2100905 is about 128.0763094782.

Adding to 2100905 its reverse (5090012), we get a palindrome (7190917).

The spelling of 2100905 in words is "two million, one hundred thousand, nine hundred five".