12499978 has 4 divisors (see below), whose sum is σ = 18749970. Its totient is φ = 6249988.

The previous prime is 12499919. The next prime is 12499987. The reversal of 12499978 is 87999421.

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., 7038409 + 5461569 = 2653^2 + 2337^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3124993 + ... + 3124996.

Almost surely, 2^12499978 is an apocalyptic number.

12499978 is a deficient number, since it is larger than the sum of its proper divisors (6249992).

12499978 is an equidigital number, since it uses as much as digits as its factorization.

12499978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6249991.

The product of its digits is 326592, while the sum is 49.

The square root of 12499978 is about 3535.5307946615. The cubic root of 12499978 is about 232.0793055273.

The spelling of 12499978 in words is "twelve million, four hundred ninety-nine thousand, nine hundred seventy-eight".