143643221 has 4 divisors (see below), whose sum is σ = 143754432. Its totient is φ = 143532012.

The previous prime is 143643169. The next prime is 143643239. The reversal of 143643221 is 122346341.

143643221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122346341 = 13 ⋅9411257.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-143643221 is a prime.

It is a super-3 number, since 3×143643221³ (a number of 25 digits) contains 333 as substring.

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 (143648221) 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, 53645 + ... + 56258.

It is an arithmetic number, because the mean of its divisors is an integer number (35938608).

Almost surely, 2^143643221 is an apocalyptic number.

It is an amenable number.

143643221 is a deficient number, since it is larger than the sum of its proper divisors (111211).

143643221 is a wasteful number, since it uses less digits than its factorization.

143643221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111210.

The product of its digits is 3456, while the sum is 26.

The square root of 143643221 is about 11985.1249889186. The cubic root of 143643221 is about 523.7150386682.

Adding to 143643221 its reverse (122346341), we get a palindrome (265989562).

The spelling of 143643221 in words is "one hundred forty-three million, six hundred forty-three thousand, two hundred twenty-one".