2106405 has 40 divisors (see below), whose sum is σ = 4321152. Its totient is φ = 961632.

The previous prime is 2106389. The next prime is 2106407. The reversal of 2106405 is 5046012.

It is a happy number.

2106405 is a `hidden beast` number, since 21 + 0 + 640 + 5 = 666.

It is not a de Polignac number, because 2106405 - 2⁴ = 2106389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2106407) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2464 + ... + 3206.

2^2106405 is an apocalyptic number.

It is an amenable number.

2106405 is an abundant number, since it is smaller than the sum of its proper divisors (2214747).

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

2106405 is an equidigital number, since it uses as much as digits as its factorization.

2106405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 2106405 is about 1451.3459270622. The cubic root of 2106405 is about 128.1879765756.

The spelling of 2106405 in words is "two million, one hundred six thousand, four hundred five".