2130805 has 4 divisors (see below), whose sum is σ = 2556972. Its totient is φ = 1704640.

The previous prime is 2130803. The next prime is 2130809. The reversal of 2130805 is 5080312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 669124 + 1461681 = 818^2 + 1209^2 .

It is not a de Polignac number, because 2130805 - 2¹ = 2130803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2130803) 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, 213076 + ... + 213085.

It is an arithmetic number, because the mean of its divisors is an integer number (639243).

2^2130805 is an apocalyptic number.

It is an amenable number.

2130805 is a deficient number, since it is larger than the sum of its proper divisors (426167).

2130805 is an equidigital number, since it uses as much as digits as its factorization.

2130805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426166.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 2130805 is about 1459.7277143358. The cubic root of 2130805 is about 128.6810420311.

The spelling of 2130805 in words is "two million, one hundred thirty thousand, eight hundred five".