12431978 has 12 divisors (see below), whose sum is σ = 20193318. Its totient is φ = 5737680.

The previous prime is 12431977. The next prime is 12432011. The reversal of 12431978 is 87913421.

It can be written as a sum of positive squares in 3 ways, for example, as 2211169 + 10220809 = 1487^2 + 3197^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (12431971) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18053 + ... + 18728.

Almost surely, 2^12431978 is an apocalyptic number.

12431978 is a deficient number, since it is larger than the sum of its proper divisors (7761340).

12431978 is a wasteful number, since it uses less digits than its factorization.

12431978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36809 (or 36796 counting only the distinct ones).

The product of its digits is 12096, while the sum is 35.

The square root of 12431978 is about 3525.9010195977. The cubic root of 12431978 is about 231.6577022105.

The spelling of 12431978 in words is "twelve million, four hundred thirty-one thousand, nine hundred seventy-eight".