13991278 has 8 divisors (see below), whose sum is σ = 23985072. Its totient is φ = 5996256.

The previous prime is 13991273. The next prime is 13991279. The reversal of 13991278 is 87219931.

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

It is a self number, because there is not a number n which added to its sum of digits gives 13991278.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13991273) 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, 499675 + ... + 499702.

It is an arithmetic number, because the mean of its divisors is an integer number (2998134).

Almost surely, 2^13991278 is an apocalyptic number.

13991278 is a deficient number, since it is larger than the sum of its proper divisors (9993794).

13991278 is an equidigital number, since it uses as much as digits as its factorization.

13991278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999386.

The product of its digits is 27216, while the sum is 40.

The square root of 13991278 is about 3740.4916789107. The cubic root of 13991278 is about 240.9641653991.

The spelling of 13991278 in words is "thirteen million, nine hundred ninety-one thousand, two hundred seventy-eight".