1664233231 has 4 divisors (see below), whose sum is σ = 1695633912. Its totient is φ = 1632832552.

The previous prime is 1664233217. The next prime is 1664233243. The reversal of 1664233231 is 1323324661.

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 1664233231 - 2¹¹ = 1664231183 is a prime.

It is a super-2 number, since 2×1664233231² = 5539344494329398722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1664233193 and 1664233202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664233201) 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, 15700261 + ... + 15700366.

It is an arithmetic number, because the mean of its divisors is an integer number (423908478).

Almost surely, 2^1664233231 is an apocalyptic number.

1664233231 is a deficient number, since it is larger than the sum of its proper divisors (31400681).

1664233231 is an equidigital number, since it uses as much as digits as its factorization.

1664233231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31400680.

The product of its digits is 15552, while the sum is 31.

The square root of 1664233231 is about 40795.0147812205. The cubic root of 1664233231 is about 1185.0537890329.

Adding to 1664233231 its reverse (1323324661), we get a palindrome (2987557892).

The spelling of 1664233231 in words is "one billion, six hundred sixty-four million, two hundred thirty-three thousand, two hundred thirty-one".