231121421 has 4 divisors (see below), whose sum is σ = 231157500. Its totient is φ = 231085344.

The previous prime is 231121417. The next prime is 231121447. The reversal of 231121421 is 124121132.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43705321 + 187416100 = 6611^2 + 13690^2 .

It is a cyclic number.

It is not a de Polignac number, because 231121421 - 2² = 231121417 is a prime.

It is a super-2 number, since 2×231121421² = 106834222490118482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231121421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231121021) 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, 5546 + ... + 22203.

It is an arithmetic number, because the mean of its divisors is an integer number (57789375).

Almost surely, 2^231121421 is an apocalyptic number.

It is an amenable number.

231121421 is a deficient number, since it is larger than the sum of its proper divisors (36079).

231121421 is an equidigital number, since it uses as much as digits as its factorization.

231121421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36078.

The product of its digits is 96, while the sum is 17.

The square root of 231121421 is about 15202.6780864425. The cubic root of 231121421 is about 613.6867307710.

Adding to 231121421 its reverse (124121132), we get a palindrome (355242553).

It can be divided in two parts, 2311 and 21421, that added together give a palindrome (23732).

The spelling of 231121421 in words is "two hundred thirty-one million, one hundred twenty-one thousand, four hundred twenty-one".