23121013520 has 40 divisors (see below), whose sum is σ = 58643300160. Its totient is φ = 8407640960.

The previous prime is 23121013501. The next prime is 23121013529. The reversal of 23121013520 is 2531012132.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 23121013492 and 23121013501.

It is not an unprimeable number, because it can be changed into a prime (23121013529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13136060 + ... + 13137819.

It is an arithmetic number, because the mean of its divisors is an integer number (1466082504).

Almost surely, 2^23121013520 is an apocalyptic number.

23121013520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23121013520 is an abundant number, since it is smaller than the sum of its proper divisors (35522286640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

23121013520 is a wasteful number, since it uses less digits than its factorization.

23121013520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26273903 (or 26273897 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

Adding to 23121013520 its reverse (2531012132), we get a palindrome (25652025652).

The spelling of 23121013520 in words is "twenty-three billion, one hundred twenty-one million, thirteen thousand, five hundred twenty".