221232431 has 8 divisors (see below), whose sum is σ = 258216960. Its totient is φ = 185592888.

The previous prime is 221232397. The next prime is 221232437. The reversal of 221232431 is 134232122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221232431 is a prime.

It is a super-3 number, since 3×221232431³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221232437) 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 7 ways as a sum of consecutive naturals, for example, 335891 + ... + 336548.

It is an arithmetic number, because the mean of its divisors is an integer number (32277120).

Almost surely, 2^221232431 is an apocalyptic number.

221232431 is a deficient number, since it is larger than the sum of its proper divisors (36984529).

221232431 is an equidigital number, since it uses as much as digits as its factorization.

221232431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672493.

The product of its digits is 576, while the sum is 20.

The square root of 221232431 is about 14873.8841934446. The cubic root of 221232431 is about 604.8062408009.

Adding to 221232431 its reverse (134232122), we get a palindrome (355464553).

It can be divided in two parts, 2212 and 32431, that added together give a palindrome (34643).

The spelling of 221232431 in words is "two hundred twenty-one million, two hundred thirty-two thousand, four hundred thirty-one".