21013011233 has 2 divisors, whose sum is σ = 21013011234. Its totient is φ = 21013011232.

The previous prime is 21013011199. The next prime is 21013011293. The reversal of 21013011233 is 33211031012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17623093504 + 3389917729 = 132752^2 + 58223^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013011233 - 2¹⁸ = 21012749089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21013011293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506505616 + 10506505617.

It is an arithmetic number, because the mean of its divisors is an integer number (10506505617).

Almost surely, 2^21013011233 is an apocalyptic number.

It is an amenable number.

21013011233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013011233 is an equidigital number, since it uses as much as digits as its factorization.

21013011233 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21013011233 its reverse (33211031012), we get a palindrome (54224042245).

The spelling of 21013011233 in words is "twenty-one billion, thirteen million, eleven thousand, two hundred thirty-three".