1143439985 has 16 divisors (see below), whose sum is σ = 1432728000. Its totient is φ = 874942656.

The previous prime is 1143439981. The next prime is 1143440003. The reversal of 1143439985 is 5899343411.

It is a cyclic number.

It is not a de Polignac number, because 1143439985 - 2² = 1143439981 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1143439981) 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, 21335 + ... + 52364.

It is an arithmetic number, because the mean of its divisors is an integer number (89545500).

Almost surely, 2^1143439985 is an apocalyptic number.

It is an amenable number.

1143439985 is a deficient number, since it is larger than the sum of its proper divisors (289288015).

1143439985 is a wasteful number, since it uses less digits than its factorization.

1143439985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73840.

The product of its digits is 466560, while the sum is 47.

The square root of 1143439985 is about 33814.7894418995. The cubic root of 1143439985 is about 1045.6936200759.

The spelling of 1143439985 in words is "one billion, one hundred forty-three million, four hundred thirty-nine thousand, nine hundred eighty-five".