221234431 has 4 divisors (see below), whose sum is σ = 241346664. Its totient is φ = 201122200.

The previous prime is 221234407. The next prime is 221234437. The reversal of 221234431 is 134432122.

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 221234431 - 2⁹ = 221233919 is a prime.

It is a super-2 number, since 2×221234431² = 97889346919787522, 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 (221234437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10056100 + ... + 10056121.

It is an arithmetic number, because the mean of its divisors is an integer number (60336666).

Almost surely, 2^221234431 is an apocalyptic number.

221234431 is a deficient number, since it is larger than the sum of its proper divisors (20112233).

221234431 is a wasteful number, since it uses less digits than its factorization.

221234431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20112232.

The product of its digits is 1152, while the sum is 22.

The square root of 221234431 is about 14873.9514252266. The cubic root of 221234431 is about 604.8080633318.

Adding to 221234431 its reverse (134432122), we get a palindrome (355666553).

The spelling of 221234431 in words is "two hundred twenty-one million, two hundred thirty-four thousand, four hundred thirty-one".