21212102331 has 48 divisors (see below), whose sum is σ = 36097963200. Its totient is φ = 11749411584.

The previous prime is 21212102297. The next prime is 21212102339. The reversal of 21212102331 is 13320121212.

21212102331 is a `hidden beast` number, since 2 + 121 + 210 + 2 + 331 = 666.

It is not a de Polignac number, because 21212102331 - 2⁶ = 21212102267 is a prime.

It is a super-3 number, since 3×21212102331³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21212102339) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 610125 + ... + 643953.

It is an arithmetic number, because the mean of its divisors is an integer number (752040900).

Almost surely, 2^21212102331 is an apocalyptic number.

21212102331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21212102331 is a deficient number, since it is larger than the sum of its proper divisors (14885860869).

21212102331 is a wasteful number, since it uses less digits than its factorization.

21212102331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34148 (or 34145 counting only the distinct ones).

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

Adding to 21212102331 its reverse (13320121212), we get a palindrome (34532223543).

The spelling of 21212102331 in words is "twenty-one billion, two hundred twelve million, one hundred two thousand, three hundred thirty-one".