13856665 has 4 divisors (see below), whose sum is σ = 16628004. Its totient is φ = 11085328.

The previous prime is 13856657. The next prime is 13856671. The reversal of 13856665 is 56665831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56665831 = 79 ⋅717289.

It can be written as a sum of positive squares in 2 ways, for example, as 6615184 + 7241481 = 2572^2 + 2691^2 .

It is a cyclic number.

It is not a de Polignac number, because 13856665 - 2³ = 13856657 is a prime.

It is a Duffinian 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, 1385662 + ... + 1385671.

It is an arithmetic number, because the mean of its divisors is an integer number (4157001).

Almost surely, 2^13856665 is an apocalyptic number.

It is an amenable number.

13856665 is a deficient number, since it is larger than the sum of its proper divisors (2771339).

13856665 is an equidigital number, since it uses as much as digits as its factorization.

13856665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2771338.

The product of its digits is 129600, while the sum is 40.

The square root of 13856665 is about 3722.4541635862. The cubic root of 13856665 is about 240.1888848696.

The spelling of 13856665 in words is "thirteen million, eight hundred fifty-six thousand, six hundred sixty-five".