21212131233 has 16 divisors (see below), whose sum is σ = 28407456000. Its totient is φ = 14079162000.

The previous prime is 21212131231. The next prime is 21212131261. The reversal of 21212131233 is 33213121212.

It is not a de Polignac number, because 21212131233 - 2¹ = 21212131231 is a prime.

It is a super-2 number, since 2×21212131233² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21212131231) 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 15 ways as a sum of consecutive naturals, for example, 2479878 + ... + 2488416.

It is an arithmetic number, because the mean of its divisors is an integer number (1775466000).

Almost surely, 2^21212131233 is an apocalyptic number.

It is an amenable number.

21212131233 is a deficient number, since it is larger than the sum of its proper divisors (7195324767).

21212131233 is a wasteful number, since it uses less digits than its factorization.

21212131233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12092.

The product of its digits is 432, while the sum is 21.

Adding to 21212131233 its reverse (33213121212), we get a palindrome (54425252445).

The spelling of 21212131233 in words is "twenty-one billion, two hundred twelve million, one hundred thirty-one thousand, two hundred thirty-three".