21013123233 has 4 divisors (see below), whose sum is σ = 28017497648. Its totient is φ = 14008748820.

The previous prime is 21013123217. The next prime is 21013123237. The reversal of 21013123233 is 33232131012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21013123233 - 2⁴ = 21013123217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013123237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3502187203 + ... + 3502187208.

It is an arithmetic number, because the mean of its divisors is an integer number (7004374412).

Almost surely, 2^21013123233 is an apocalyptic number.

It is an amenable number.

21013123233 is a deficient number, since it is larger than the sum of its proper divisors (7004374415).

21013123233 is an equidigital number, since it uses as much as digits as its factorization.

21013123233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7004374414.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21013123233 its reverse (33232131012), we get a palindrome (54245254245).

The spelling of 21013123233 in words is "twenty-one billion, thirteen million, one hundred twenty-three thousand, two hundred thirty-three".