13939778 has 8 divisors (see below), whose sum is σ = 21630780. Its totient is φ = 6729520.

The previous prime is 13939769. The next prime is 13939831. The reversal of 13939778 is 87793931.

It can be written as a sum of positive squares in 2 ways, for example, as 13935289 + 4489 = 3733^2 + 67^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon 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, 120113 + ... + 120228.

Almost surely, 2^13939778 is an apocalyptic number.

13939778 is a deficient number, since it is larger than the sum of its proper divisors (7691002).

13939778 is a wasteful number, since it uses less digits than its factorization.

13939778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240372.

The product of its digits is 285768, while the sum is 47.

The square root of 13939778 is about 3733.6012106276. The cubic root of 13939778 is about 240.6681497476.

The spelling of 13939778 in words is "thirteen million, nine hundred thirty-nine thousand, seven hundred seventy-eight".