1268939891 has 8 divisors (see below), whose sum is σ = 1343909520. Its totient is φ = 1194006528.

The previous prime is 1268939851. The next prime is 1268939911. The reversal of 1268939891 is 1989398621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1268939891 - 2²⁶ = 1201831027 is a prime.

It is a super-2 number, since 2×1268939891² = 3220416893942183762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1268939851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101840 + ... + 113618.

It is an arithmetic number, because the mean of its divisors is an integer number (167988690).

Almost surely, 2^1268939891 is an apocalyptic number.

1268939891 is a deficient number, since it is larger than the sum of its proper divisors (74969629).

1268939891 is a wasteful number, since it uses less digits than its factorization.

1268939891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18133.

The product of its digits is 1679616, while the sum is 56.

The square root of 1268939891 is about 35622.1825692924. The cubic root of 1268939891 is about 1082.6307297664.

The spelling of 1268939891 in words is "one billion, two hundred sixty-eight million, nine hundred thirty-nine thousand, eight hundred ninety-one".