23121343521 has 48 divisors (see below), whose sum is σ = 34832711680. Its totient is φ = 14762774880.

The previous prime is 23121343501. The next prime is 23121343529. The reversal of 23121343521 is 12534312132.

23121343521 is a `hidden beast` number, since 2 + 3 + 1 + 2 + 134 + 3 + 521 = 666.

It is not a de Polignac number, because 23121343521 - 2⁶ = 23121343457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23121343529) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26184546 + ... + 26185428.

Almost surely, 2^23121343521 is an apocalyptic number.

It is an amenable number.

23121343521 is a deficient number, since it is larger than the sum of its proper divisors (11711368159).

23121343521 is a wasteful number, since it uses less digits than its factorization.

23121343521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1786 (or 1783 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

Adding to 23121343521 its reverse (12534312132), we get a palindrome (35655655653).

The spelling of 23121343521 in words is "twenty-three billion, one hundred twenty-one million, three hundred forty-three thousand, five hundred twenty-one".