21243032245 has 4 divisors (see below), whose sum is σ = 25491638700. Its totient is φ = 16994425792.

The previous prime is 21243032233. The next prime is 21243032249. The reversal of 21243032245 is 54223034212.

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 9320357764 + 11922674481 = 96542^2 + 109191^2 .

It is a cyclic number.

It is not a de Polignac number, because 21243032245 - 2⁷ = 21243032117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243032249) 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, 2124303220 + ... + 2124303229.

It is an arithmetic number, because the mean of its divisors is an integer number (6372909675).

Almost surely, 2^21243032245 is an apocalyptic number.

It is an amenable number.

21243032245 is a deficient number, since it is larger than the sum of its proper divisors (4248606455).

21243032245 is an equidigital number, since it uses as much as digits as its factorization.

21243032245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4248606454.

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 21243032245 its reverse (54223034212), we get a palindrome (75466066457).

The spelling of 21243032245 in words is "twenty-one billion, two hundred forty-three million, thirty-two thousand, two hundred forty-five".