21212331131 has 2 divisors, whose sum is σ = 21212331132. Its totient is φ = 21212331130.

The previous prime is 21212331121. The next prime is 21212331193. The reversal of 21212331131 is 13113321212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212331131 is a prime.

It is a super-2 number, since 2×21212331131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21212331121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606165565 + 10606165566.

It is an arithmetic number, because the mean of its divisors is an integer number (10606165566).

Almost surely, 2^21212331131 is an apocalyptic number.

21212331131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212331131 is an equidigital number, since it uses as much as digits as its factorization.

21212331131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

Adding to 21212331131 its reverse (13113321212), we get a palindrome (34325652343).

The spelling of 21212331131 in words is "twenty-one billion, two hundred twelve million, three hundred thirty-one thousand, one hundred thirty-one".