1143857891 has 12 divisors (see below), whose sum is σ = 1258145952. Its totient is φ = 1039170000.

The previous prime is 1143857887. The next prime is 1143857899. The reversal of 1143857891 is 1987583411.

It is not a de Polignac number, because 1143857891 - 2² = 1143857887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1143857899) 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, 282461 + ... + 286481.

It is an arithmetic number, because the mean of its divisors is an integer number (104845496).

Almost surely, 2^1143857891 is an apocalyptic number.

1143857891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1143857891 is a deficient number, since it is larger than the sum of its proper divisors (114288061).

1143857891 is a wasteful number, since it uses less digits than its factorization.

1143857891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6394 (or 6383 counting only the distinct ones).

The product of its digits is 241920, while the sum is 47.

The square root of 1143857891 is about 33820.9682149994. The cubic root of 1143857891 is about 1045.8209984009.

The spelling of 1143857891 in words is "one billion, one hundred forty-three million, eight hundred fifty-seven thousand, eight hundred ninety-one".