1256978166 has 16 divisors (see below), whose sum is σ = 2514632688. Its totient is φ = 418880000.

The previous prime is 1256978161. The next prime is 1256978179. The reversal of 1256978166 is 6618796521.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256978161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2175 + ... + 50186.

It is an arithmetic number, because the mean of its divisors is an integer number (157164543).

Almost surely, 2^1256978166 is an apocalyptic number.

1256978166 is an abundant number, since it is smaller than the sum of its proper divisors (1257654522).

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

1256978166 is a wasteful number, since it uses less digits than its factorization.

1256978166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56367.

The product of its digits is 1088640, while the sum is 51.

The square root of 1256978166 is about 35453.8878827132. The cubic root of 1256978166 is about 1079.2181601370.

The spelling of 1256978166 in words is "one billion, two hundred fifty-six million, nine hundred seventy-eight thousand, one hundred sixty-six".