221143631 has 4 divisors (see below), whose sum is σ = 221222112. Its totient is φ = 221065152.

The previous prime is 221143621. The next prime is 221143661. The reversal of 221143631 is 136341122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221143631 is a prime.

It is a super-2 number, since 2×221143631² = 97809011063728322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221143597 and 221143606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221143621) 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, 34850 + ... + 40703.

It is an arithmetic number, because the mean of its divisors is an integer number (55305528).

Almost surely, 2^221143631 is an apocalyptic number.

221143631 is a deficient number, since it is larger than the sum of its proper divisors (78481).

221143631 is an equidigital number, since it uses as much as digits as its factorization.

221143631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78480.

The product of its digits is 864, while the sum is 23.

The square root of 221143631 is about 14870.8987959706. The cubic root of 221143631 is about 604.7253093550.

Adding to 221143631 its reverse (136341122), we get a palindrome (357484753).

The spelling of 221143631 in words is "two hundred twenty-one million, one hundred forty-three thousand, six hundred thirty-one".