21021212311331 has 2 divisors, whose sum is σ = 21021212311332. Its totient is φ = 21021212311330.

The previous prime is 21021212311219. The next prime is 21021212311453. The reversal of 21021212311331 is 13311321212012.

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-21021212311331 is a prime.

It is a super-2 number, since 2×21021212311331² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21021212311297 and 21021212311306.

It is not a weakly prime, because it can be changed into another prime (21021212311531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510606155665 + 10510606155666.

It is an arithmetic number, because the mean of its divisors is an integer number (10510606155666).

Almost surely, 2^{21021212311331} is an apocalyptic number.

21021212311331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021212311331 is an equidigital number, since it uses as much as digits as its factorization.

21021212311331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21021212311331 its reverse (13311321212012), we get a palindrome (34332533523343).

The spelling of 21021212311331 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, three hundred eleven thousand, three hundred thirty-one".