21212301231 has 12 divisors (see below), whose sum is σ = 33425444520. Its totient is φ = 12855940080.

The previous prime is 21212301203. The next prime is 21212301251. The reversal of 21212301231 is 13210321212.

It is not a de Polignac number, because 21212301231 - 2¹¹ = 21212299183 is a prime.

It is a super-2 number, since 2×21212301231² (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 (21212301251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107132736 + ... + 107132933.

It is an arithmetic number, because the mean of its divisors is an integer number (2785453710).

Almost surely, 2^21212301231 is an apocalyptic number.

21212301231 is a deficient number, since it is larger than the sum of its proper divisors (12213143289).

21212301231 is a wasteful number, since it uses less digits than its factorization.

21212301231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214265686 (or 214265683 counting only the distinct ones).

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

Adding to 21212301231 its reverse (13210321212), we get a palindrome (34422622443).

The spelling of 21212301231 in words is "twenty-one billion, two hundred twelve million, three hundred one thousand, two hundred thirty-one".