21524500145 has 4 divisors (see below), whose sum is σ = 25829400180. Its totient is φ = 17219600112.

The previous prime is 21524500117. The next prime is 21524500181. The reversal of 21524500145 is 54100542512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15653262769 + 5871237376 = 125113^2 + 76624^2 .

It is a cyclic number.

It is not a de Polignac number, because 21524500145 - 2²² = 21520305841 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2152450010 + ... + 2152450019.

It is an arithmetic number, because the mean of its divisors is an integer number (6457350045).

Almost surely, 2^21524500145 is an apocalyptic number.

It is an amenable number.

21524500145 is a deficient number, since it is larger than the sum of its proper divisors (4304900035).

21524500145 is an equidigital number, since it uses as much as digits as its factorization.

21524500145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4304900034.

The product of its (nonzero) digits is 8000, while the sum is 29.

The spelling of 21524500145 in words is "twenty-one billion, five hundred twenty-four million, five hundred thousand, one hundred forty-five".