13978765 has 4 divisors (see below), whose sum is σ = 16774524. Its totient is φ = 11183008.

The previous prime is 13978759. The next prime is 13978793. The reversal of 13978765 is 56787931.

13978765 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.

It can be written as a sum of positive squares in 2 ways, for example, as 11095561 + 2883204 = 3331^2 + 1698^2 .

It is a cyclic number.

It is not a de Polignac number, because 13978765 - 2¹¹ = 13976717 is a prime.

It is a Duffinian number.

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, 1397872 + ... + 1397881.

It is an arithmetic number, because the mean of its divisors is an integer number (4193631).

Almost surely, 2^13978765 is an apocalyptic number.

It is an amenable number.

13978765 is a deficient number, since it is larger than the sum of its proper divisors (2795759).

13978765 is an equidigital number, since it uses as much as digits as its factorization.

13978765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2795758.

The product of its digits is 317520, while the sum is 46.

The square root of 13978765 is about 3738.8186636958. The cubic root of 13978765 is about 240.8923091107.

The spelling of 13978765 in words is "thirteen million, nine hundred seventy-eight thousand, seven hundred sixty-five".