231212213230221 has 16 divisors (see below), whose sum is σ = 342551183579200. Its totient is φ = 154134918363024.

The previous prime is 231212213230183. The next prime is 231212213230267. The reversal of 231212213230221 is 122032312212132.

231212213230221 is a `hidden beast` number, since 2 + 3 + 1 + 212 + 213 + 230 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 231212213230221 - 2²¹ = 231212211133069 is a prime.

It is a super-2 number, since 2×231212213230221² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212213230421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181495831 + ... + 182765316.

It is an arithmetic number, because the mean of its divisors is an integer number (21409448973700).

Almost surely, 2^{231212213230221} is an apocalyptic number.

It is an amenable number.

231212213230221 is a deficient number, since it is larger than the sum of its proper divisors (111338970348979).

231212213230221 is a wasteful number, since it uses less digits than its factorization.

231212213230221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364284665 (or 364284659 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 231212213230221 its reverse (122032312212132), we get a palindrome (353244525442353).

The spelling of 231212213230221 in words is "two hundred thirty-one trillion, two hundred twelve billion, two hundred thirteen million, two hundred thirty thousand, two hundred twenty-one".