12432778 has 4 divisors (see below), whose sum is σ = 18649170. Its totient is φ = 6216388.

The previous prime is 12432773. The next prime is 12432779. The reversal of 12432778 is 87723421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87723421 = 4943 ⋅17747.

It can be written as a sum of positive squares in only one way, i.e., 10131489 + 2301289 = 3183^2 + 1517^2 .

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (12432773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3108193 + ... + 3108196.

Almost surely, 2^12432778 is an apocalyptic number.

12432778 is a deficient number, since it is larger than the sum of its proper divisors (6216392).

12432778 is an equidigital number, since it uses as much as digits as its factorization.

12432778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6216391.

The product of its digits is 18816, while the sum is 34.

The square root of 12432778 is about 3526.0144639522. The cubic root of 12432778 is about 231.6626711754.

The spelling of 12432778 in words is "twelve million, four hundred thirty-two thousand, seven hundred seventy-eight".