2131765 has 4 divisors (see below), whose sum is σ = 2558124. Its totient is φ = 1705408.

The previous prime is 2131721. The next prime is 2131771. The reversal of 2131765 is 5671312.

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 1454436 + 677329 = 1206^2 + 823^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131765 - 2⁹ = 2131253 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213172 + ... + 213181.

It is an arithmetic number, because the mean of its divisors is an integer number (639531).

2^2131765 is an apocalyptic number.

It is an amenable number.

2131765 is a deficient number, since it is larger than the sum of its proper divisors (426359).

2131765 is an equidigital number, since it uses as much as digits as its factorization.

2131765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426358.

The product of its digits is 1260, while the sum is 25.

The square root of 2131765 is about 1460.0565057559. The cubic root of 2131765 is about 128.7003641892.

The spelling of 2131765 in words is "two million, one hundred thirty-one thousand, seven hundred sixty-five".