1665143231 has 4 divisors (see below), whose sum is σ = 1665307512. Its totient is φ = 1664978952.

The previous prime is 1665143219. The next prime is 1665143239. The reversal of 1665143231 is 1323415661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1665143231 - 2¹⁴ = 1665126847 is a prime.

It is a super-2 number, since 2×1665143231² = 5545403959490238722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665143239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65861 + ... + 87566.

It is an arithmetic number, because the mean of its divisors is an integer number (416326878).

Almost surely, 2^1665143231 is an apocalyptic number.

1665143231 is a deficient number, since it is larger than the sum of its proper divisors (164281).

1665143231 is a wasteful number, since it uses less digits than its factorization.

1665143231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164280.

The product of its digits is 12960, while the sum is 32.

The square root of 1665143231 is about 40806.1665805550. The cubic root of 1665143231 is about 1185.2697448321.

Adding to 1665143231 its reverse (1323415661), we get a palindrome (2988558892).

The spelling of 1665143231 in words is "one billion, six hundred sixty-five million, one hundred forty-three thousand, two hundred thirty-one".