2123665 has 8 divisors (see below), whose sum is σ = 2557800. Its totient is φ = 1692672.

The previous prime is 2123663. The next prime is 2123669. The reversal of 2123665 is 5663212.

It can be written as a sum of positive squares in 4 ways, for example, as 263169 + 1860496 = 513^2 + 1364^2 .

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 2123665 - 2¹ = 2123663 is a prime.

It is a d-powerful number, because it can be written as 2¹² + 1 + 2¹⁸ + 3¹¹ + 6² + 6⁸ + 5⁴ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123663) 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, 1137 + ... + 2353.

It is an arithmetic number, because the mean of its divisors is an integer number (319725).

2^2123665 is an apocalyptic number.

It is an amenable number.

2123665 is a deficient number, since it is larger than the sum of its proper divisors (434135).

2123665 is a wasteful number, since it uses less digits than its factorization.

2123665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571.

The product of its digits is 2160, while the sum is 25.

The square root of 2123665 is about 1457.2800005490. The cubic root of 2123665 is about 128.5371510622.

Adding to 2123665 its reverse (5663212), we get a palindrome (7786877).

The spelling of 2123665 in words is "two million, one hundred twenty-three thousand, six hundred sixty-five".