21242213231 has 2 divisors, whose sum is σ = 21242213232. Its totient is φ = 21242213230.

The previous prime is 21242213221. The next prime is 21242213257. The reversal of 21242213231 is 13231224212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21242213231 is a prime.

It is a super-2 number, since 2×21242213231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21242213197 and 21242213206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21242213221) 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 as a sum of consecutive naturals, namely, 10621106615 + 10621106616.

It is an arithmetic number, because the mean of its divisors is an integer number (10621106616).

Almost surely, 2^21242213231 is an apocalyptic number.

21242213231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21242213231 is an equidigital number, since it uses as much as digits as its factorization.

21242213231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 23.

Adding to 21242213231 its reverse (13231224212), we get a palindrome (34473437443).

The spelling of 21242213231 in words is "twenty-one billion, two hundred forty-two million, two hundred thirteen thousand, two hundred thirty-one".