21212310231 has 12 divisors (see below), whose sum is σ = 35017147152. Its totient is φ = 12121320096.

The previous prime is 21212310221. The next prime is 21212310233. The reversal of 21212310231 is 13201321212.

21212310231 is a `hidden beast` number, since 2 + 121 + 2 + 310 + 231 = 666.

It is not a de Polignac number, because 21212310231 - 2⁷ = 21212310103 is a prime.

It is a super-2 number, since 2×21212310231² (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 (21212310233) 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, 168351606 + ... + 168351731.

It is an arithmetic number, because the mean of its divisors is an integer number (2918095596).

Almost surely, 2^21212310231 is an apocalyptic number.

21212310231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21212310231 is a deficient number, since it is larger than the sum of its proper divisors (13804836921).

21212310231 is a wasteful number, since it uses less digits than its factorization.

21212310231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336703350 (or 336703347 counting only the distinct ones).

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

Adding to 21212310231 its reverse (13201321212), we get a palindrome (34413631443).

The spelling of 21212310231 in words is "twenty-one billion, two hundred twelve million, three hundred ten thousand, two hundred thirty-one".