13723978 has 8 divisors (see below), whose sum is σ = 20817540. Its totient is φ = 6784800.

The previous prime is 13723973. The next prime is 13723987. The reversal of 13723978 is 87932731.

It can be written as a sum of positive squares in 2 ways, for example, as 13667809 + 56169 = 3697^2 + 237^2 .

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 13723978.

It is not an unprimeable number, because it can be changed into a prime (13723973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38373 + ... + 38728.

Almost surely, 2^13723978 is an apocalyptic number.

13723978 is a deficient number, since it is larger than the sum of its proper divisors (7093562).

13723978 is an equidigital number, since it uses as much as digits as its factorization.

13723978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77192.

The product of its digits is 63504, while the sum is 40.

The square root of 13723978 is about 3704.5887760992. The cubic root of 13723978 is about 239.4197673205.

The spelling of 13723978 in words is "thirteen million, seven hundred twenty-three thousand, nine hundred seventy-eight".