2101906 has 8 divisors (see below), whose sum is σ = 3229884. Its totient is φ = 1025280.

The previous prime is 2101903. The next prime is 2101907. The reversal of 2101906 is 6091012.

It can be written as a sum of positive squares in 2 ways, for example, as 1846881 + 255025 = 1359^2 + 505^2 .

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

It is not an unprimeable number, because it can be changed into a prime (2101903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12735 + ... + 12898.

2^2101906 is an apocalyptic number.

2101906 is a deficient number, since it is larger than the sum of its proper divisors (1127978).

2101906 is a wasteful number, since it uses less digits than its factorization.

2101906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25676.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 2101906 is about 1449.7951579447. The cubic root of 2101906 is about 128.0966473849.

Adding to 2101906 its reverse (6091012), we get a palindrome (8192918).

It can be divided in two parts, 210 and 1906, that added together give a square (2116 = 46²).

The spelling of 2101906 in words is "two million, one hundred one thousand, nine hundred six".