1118943891 has 12 divisors (see below), whose sum is σ = 1740579568. Its totient is φ = 688580784.

The previous prime is 1118943887. The next prime is 1118943919. The reversal of 1118943891 is 1983498111.

It is a happy number.

It is not a de Polignac number, because 1118943891 - 2² = 1118943887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1118943851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4781695 + ... + 4781928.

Almost surely, 2^1118943891 is an apocalyptic number.

1118943891 is a deficient number, since it is larger than the sum of its proper divisors (621635677).

1118943891 is a wasteful number, since it uses less digits than its factorization.

1118943891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9563642 (or 9563639 counting only the distinct ones).

The product of its digits is 62208, while the sum is 45.

The square root of 1118943891 is about 33450.6186938299. The cubic root of 1118943891 is about 1038.1722986841.

The spelling of 1118943891 in words is "one billion, one hundred eighteen million, nine hundred forty-three thousand, eight hundred ninety-one".