1268178891 has 16 divisors (see below), whose sum is σ = 1933075200. Its totient is φ = 724444128.

The previous prime is 1268178887. The next prime is 1268178931. The reversal of 1268178891 is 1988718621.

It is a happy number.

It is not a de Polignac number, because 1268178891 - 2² = 1268178887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1268178841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76200 + ... + 91338.

It is an arithmetic number, because the mean of its divisors is an integer number (120817200).

Almost surely, 2^1268178891 is an apocalyptic number.

1268178891 is a deficient number, since it is larger than the sum of its proper divisors (664896309).

1268178891 is a wasteful number, since it uses less digits than its factorization.

1268178891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19138.

The product of its digits is 387072, while the sum is 51.

The square root of 1268178891 is about 35611.4994208332. The cubic root of 1268178891 is about 1082.4142638425.

The spelling of 1268178891 in words is "one billion, two hundred sixty-eight million, one hundred seventy-eight thousand, eight hundred ninety-one".