13665779 has 4 divisors (see below), whose sum is σ = 13679376. Its totient is φ = 13652184.

The previous prime is 13665763. The next prime is 13665791. The reversal of 13665779 is 97756631.

13665779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97756631 = 7 ⋅13965233.

It is a cyclic number.

It is not a de Polignac number, because 13665779 - 2⁴ = 13665763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13665709) 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, 5159 + ... + 7344.

It is an arithmetic number, because the mean of its divisors is an integer number (3419844).

Almost surely, 2^13665779 is an apocalyptic number.

13665779 is a deficient number, since it is larger than the sum of its proper divisors (13597).

13665779 is a wasteful number, since it uses less digits than its factorization.

13665779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13596.

The product of its digits is 238140, while the sum is 44.

The square root of 13665779 is about 3696.7254428751. The cubic root of 13665779 is about 239.0808535811.

The spelling of 13665779 in words is "thirteen million, six hundred sixty-five thousand, seven hundred seventy-nine".