12566778 has 24 divisors (see below), whose sum is σ = 28776672. Its totient is φ = 3583944.

The previous prime is 12566761. The next prime is 12566789. The reversal of 12566778 is 87766521.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22701 + ... + 23247.

It is an arithmetic number, because the mean of its divisors is an integer number (1199028).

Almost surely, 2^12566778 is an apocalyptic number.

12566778 is an abundant number, since it is smaller than the sum of its proper divisors (16209894).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12566778 is an frugal number, since it uses more digits than its factorization.

12566778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 559 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The square root of 12566778 is about 3544.9651620291. The cubic root of 12566778 is about 232.4919826117.

Multiplying 12566778 by its sum of digits (42), we get a square (527804676 = 22974²).

12566778 divided by its sum of digits (42) gives a square (299209 = 547²).

The spelling of 12566778 in words is "twelve million, five hundred sixty-six thousand, seven hundred seventy-eight".