21530302453 has 4 divisors (see below), whose sum is σ = 23487602688. Its totient is φ = 19573002220.

The previous prime is 21530302441. The next prime is 21530302513. The reversal of 21530302453 is 35420303512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21530302453 - 2⁹ = 21530301941 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530302433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 978650101 + ... + 978650122.

It is an arithmetic number, because the mean of its divisors is an integer number (5871900672).

Almost surely, 2^21530302453 is an apocalyptic number.

It is an amenable number.

21530302453 is a deficient number, since it is larger than the sum of its proper divisors (1957300235).

21530302453 is a wasteful number, since it uses less digits than its factorization.

21530302453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957300234.

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 21530302453 its reverse (35420303512), we get a palindrome (56950605965).

The spelling of 21530302453 in words is "twenty-one billion, five hundred thirty million, three hundred two thousand, four hundred fifty-three".