21311123233 has 2 divisors, whose sum is σ = 21311123234. Its totient is φ = 21311123232.

The previous prime is 21311123219. The next prime is 21311123263. The reversal of 21311123233 is 33232111312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12961367104 + 8349756129 = 113848^2 + 91377^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311123233 is a prime.

It is a super-2 number, since 2×21311123233² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21311123263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655561616 + 10655561617.

It is an arithmetic number, because the mean of its divisors is an integer number (10655561617).

Almost surely, 2^21311123233 is an apocalyptic number.

It is an amenable number.

21311123233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311123233 is an equidigital number, since it uses as much as digits as its factorization.

21311123233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 22.

Adding to 21311123233 its reverse (33232111312), we get a palindrome (54543234545).

The spelling of 21311123233 in words is "twenty-one billion, three hundred eleven million, one hundred twenty-three thousand, two hundred thirty-three".