21123434233 has 12 divisors (see below), whose sum is σ = 23619518064. Its totient is φ = 18734736800.

The previous prime is 21123434203. The next prime is 21123434257. The reversal of 21123434233 is 33243432112.

It is a happy number.

It is not a de Polignac number, because 21123434233 - 2¹⁷ = 21123303161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123434203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 552691 + ... + 589672.

It is an arithmetic number, because the mean of its divisors is an integer number (1968293172).

Almost surely, 2^21123434233 is an apocalyptic number.

It is an amenable number.

21123434233 is a deficient number, since it is larger than the sum of its proper divisors (2496083831).

21123434233 is a wasteful number, since it uses less digits than its factorization.

21123434233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142456 (or 1142415 counting only the distinct ones).

The product of its digits is 10368, while the sum is 28.

Adding to 21123434233 its reverse (33243432112), we get a palindrome (54366866345).

The spelling of 21123434233 in words is "twenty-one billion, one hundred twenty-three million, four hundred thirty-four thousand, two hundred thirty-three".