143665661 has 4 divisors (see below), whose sum is σ = 143999424. Its totient is φ = 143331900.

The previous prime is 143665619. The next prime is 143665663. The reversal of 143665661 is 166566341.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-143665661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (143665663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166235 + ... + 167096.

It is an arithmetic number, because the mean of its divisors is an integer number (35999856).

Almost surely, 2^143665661 is an apocalyptic number.

It is an amenable number.

143665661 is a deficient number, since it is larger than the sum of its proper divisors (333763).

143665661 is an equidigital number, since it uses as much as digits as its factorization.

143665661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333762.

The product of its digits is 77760, while the sum is 38.

The square root of 143665661 is about 11986.0611128093. The cubic root of 143665661 is about 523.7423089041.

The spelling of 143665661 in words is "one hundred forty-three million, six hundred sixty-five thousand, six hundred sixty-one".