20121213231 has 24 divisors (see below), whose sum is σ = 34361352480. Its totient is φ = 11101358016.

The previous prime is 20121213187. The next prime is 20121213239. The reversal of 20121213231 is 13231212102.

20121213231 is a `hidden beast` number, since 201 + 21 + 213 + 231 = 666.

It is not a de Polignac number, because 20121213231 - 2¹⁰ = 20121212207 is a prime.

It is a super-2 number, since 2×20121213231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121213239) 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 23 ways as a sum of consecutive naturals, for example, 5504800 + ... + 5508453.

It is an arithmetic number, because the mean of its divisors is an integer number (1431723020).

Almost surely, 2^20121213231 is an apocalyptic number.

20121213231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20121213231 is a deficient number, since it is larger than the sum of its proper divisors (14240139249).

20121213231 is a wasteful number, since it uses less digits than its factorization.

20121213231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11013295 (or 11013292 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 20121213231 its reverse (13231212102), we get a palindrome (33352425333).

The spelling of 20121213231 in words is "twenty billion, one hundred twenty-one million, two hundred thirteen thousand, two hundred thirty-one".