21248214571 has 4 divisors (see below), whose sum is σ = 21248515512. Its totient is φ = 21247913632.

The previous prime is 21248214569. The next prime is 21248214593. The reversal of 21248214571 is 17541284212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21248214571 - 2¹ = 21248214569 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21248214571.

It is not an unprimeable number, because it can be changed into a prime (21248814571) 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, 19251 + ... + 207043.

It is an arithmetic number, because the mean of its divisors is an integer number (5312128878).

Almost surely, 2^21248214571 is an apocalyptic number.

21248214571 is a deficient number, since it is larger than the sum of its proper divisors (300941).

21248214571 is a wasteful number, since it uses less digits than its factorization.

21248214571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300940.

The product of its digits is 35840, while the sum is 37.

Adding to 21248214571 its reverse (17541284212), we get a palindrome (38789498783).

The spelling of 21248214571 in words is "twenty-one billion, two hundred forty-eight million, two hundred fourteen thousand, five hundred seventy-one".