23505543521 has 4 divisors (see below), whose sum is σ = 24052184112. Its totient is φ = 22958902932.

The previous prime is 23505543497. The next prime is 23505543547. The reversal of 23505543521 is 12534550532.

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 a cyclic number.

It is not a de Polignac number, because 23505543521 - 2¹⁴ = 23505527137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23505549521) 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, 273320231 + ... + 273320316.

It is an arithmetic number, because the mean of its divisors is an integer number (6013046028).

Almost surely, 2^23505543521 is an apocalyptic number.

It is an amenable number.

23505543521 is a deficient number, since it is larger than the sum of its proper divisors (546640591).

23505543521 is an equidigital number, since it uses as much as digits as its factorization.

23505543521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546640590.

The product of its (nonzero) digits is 90000, while the sum is 35.

The spelling of 23505543521 in words is "twenty-three billion, five hundred five million, five hundred forty-three thousand, five hundred twenty-one".