21523464521 has 8 divisors (see below), whose sum is σ = 23192408064. Its totient is φ = 19856419920.

The previous prime is 21523464511. The next prime is 21523464569. The reversal of 21523464521 is 12546432512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21523464521 - 2¹⁰ = 21523463497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21523464511) 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, 451145 + ... + 496566.

It is an arithmetic number, because the mean of its divisors is an integer number (2899051008).

Almost surely, 2^21523464521 is an apocalyptic number.

It is an amenable number.

21523464521 is a deficient number, since it is larger than the sum of its proper divisors (1668943543).

21523464521 is a wasteful number, since it uses less digits than its factorization.

21523464521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 949471.

The product of its digits is 57600, while the sum is 35.

The spelling of 21523464521 in words is "twenty-one billion, five hundred twenty-three million, four hundred sixty-four thousand, five hundred twenty-one".