2131565 has 8 divisors (see below), whose sum is σ = 2577120. Its totient is φ = 1692432.

The previous prime is 2131559. The next prime is 2131567. The reversal of 2131565 is 5651312.

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 2131565 - 2¹⁴ = 2115181 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2131565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 839 + ... + 2228.

It is an arithmetic number, because the mean of its divisors is an integer number (322140).

2^2131565 is an apocalyptic number.

It is an amenable number.

2131565 is a deficient number, since it is larger than the sum of its proper divisors (445555).

2131565 is a wasteful number, since it uses less digits than its factorization.

2131565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3211.

The product of its digits is 900, while the sum is 23.

The square root of 2131565 is about 1459.9880136494. The cubic root of 2131565 is about 128.6963392180.

Adding to 2131565 its reverse (5651312), we get a palindrome (7782877).

The spelling of 2131565 in words is "two million, one hundred thirty-one thousand, five hundred sixty-five".