231212421 has 32 divisors (see below), whose sum is σ = 375459840. Its totient is φ = 139460400.

The previous prime is 231212383. The next prime is 231212431. The reversal of 231212421 is 124212132.

It is a happy number.

231212421 is a `hidden beast` number, since 2 + 31 + 212 + 421 = 666.

It is not a de Polignac number, because 231212421 - 2¹³ = 231204229 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 231212394 and 231212403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64486 + ... + 67976.

It is an arithmetic number, because the mean of its divisors is an integer number (11733120).

Almost surely, 2^231212421 is an apocalyptic number.

It is an amenable number.

231212421 is a deficient number, since it is larger than the sum of its proper divisors (144247419).

231212421 is a wasteful number, since it uses less digits than its factorization.

231212421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3734 (or 3728 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 231212421 is about 15205.6706856357. The cubic root of 231212421 is about 613.7672629930.

Adding to 231212421 its reverse (124212132), we get a palindrome (355424553).

The spelling of 231212421 in words is "two hundred thirty-one million, two hundred twelve thousand, four hundred twenty-one".