13927978 has 4 divisors (see below), whose sum is σ = 20891970. Its totient is φ = 6963988.

The previous prime is 13927961. The next prime is 13927993. The reversal of 13927978 is 87972931.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 8105409 + 5822569 = 2847^2 + 2413^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3481993 + ... + 3481996.

Almost surely, 2^13927978 is an apocalyptic number.

13927978 is a deficient number, since it is larger than the sum of its proper divisors (6963992).

13927978 is an equidigital number, since it uses as much as digits as its factorization.

13927978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6963991.

The product of its digits is 190512, while the sum is 46.

The square root of 13927978 is about 3732.0206323117. The cubic root of 13927978 is about 240.6002221746.

The spelling of 13927978 in words is "thirteen million, nine hundred twenty-seven thousand, nine hundred seventy-eight".