12555778 has 4 divisors (see below), whose sum is σ = 18833670. Its totient is φ = 6277888.

The previous prime is 12555757. The next prime is 12555779. The reversal of 12555778 is 87755521.

12555778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 7112889 + 5442889 = 2667^2 + 2333^2 .

It is a super-2 number, since 2×12555778² = 315295122370568, which contains 22 as substring.

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 12555778.

It is not an unprimeable number, because it can be changed into a prime (12555779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3138943 + ... + 3138946.

Almost surely, 2^12555778 is an apocalyptic number.

12555778 is a deficient number, since it is larger than the sum of its proper divisors (6277892).

12555778 is an equidigital number, since it uses as much as digits as its factorization.

12555778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6277891.

The product of its digits is 98000, while the sum is 40.

The square root of 12555778 is about 3543.4133261588. The cubic root of 12555778 is about 232.4241275535.

The spelling of 12555778 in words is "twelve million, five hundred fifty-five thousand, seven hundred seventy-eight".