231212021 has 8 divisors (see below), whose sum is σ = 237838944. Its totient is φ = 224676720.

The previous prime is 231211961. The next prime is 231212057. The reversal of 231212021 is 120212132.

It is a happy number.

231212021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 231212021 - 2⁶ = 231211957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231211987 and 231212005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17771 + ... + 27896.

It is an arithmetic number, because the mean of its divisors is an integer number (29729868).

Almost surely, 2^231212021 is an apocalyptic number.

It is an amenable number.

231212021 is a deficient number, since it is larger than the sum of its proper divisors (6626923).

231212021 is an equidigital number, since it uses as much as digits as its factorization.

231212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45811.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 231212021 is about 15205.6575326423. The cubic root of 231212021 is about 613.7669090514.

Adding to 231212021 its reverse (120212132), we get a palindrome (351424153).

The spelling of 231212021 in words is "two hundred thirty-one million, two hundred twelve thousand, twenty-one".