21523545545 has 8 divisors (see below), whose sum is σ = 25848268800. Its totient is φ = 17205493680.

The previous prime is 21523545529. The next prime is 21523545581. The reversal of 21523545545 is 54554532512.

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

It is not a de Polignac number, because 21523545545 - 2⁴ = 21523545529 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1660745 + ... + 1673654.

It is an arithmetic number, because the mean of its divisors is an integer number (3231033600).

Almost surely, 2^21523545545 is an apocalyptic number.

It is an amenable number.

21523545545 is a deficient number, since it is larger than the sum of its proper divisors (4324723255).

21523545545 is a wasteful number, since it uses less digits than its factorization.

21523545545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3335695.

The product of its digits is 600000, while the sum is 41.

The spelling of 21523545545 in words is "twenty-one billion, five hundred twenty-three million, five hundred forty-five thousand, five hundred forty-five".