21045212453 has 16 divisors (see below), whose sum is σ = 21640050432. Its totient is φ = 20460384000.

The previous prime is 21045212437. The next prime is 21045212473. The reversal of 21045212453 is 35421254012.

It is a cyclic number.

It is not a de Polignac number, because 21045212453 - 2⁴ = 21045212437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045212473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1756463 + ... + 1768403.

It is an arithmetic number, because the mean of its divisors is an integer number (1352503152).

Almost surely, 2^21045212453 is an apocalyptic number.

It is an amenable number.

21045212453 is a deficient number, since it is larger than the sum of its proper divisors (594837979).

21045212453 is a wasteful number, since it uses less digits than its factorization.

21045212453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12356.

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 21045212453 its reverse (35421254012), we get a palindrome (56466466465).

The spelling of 21045212453 in words is "twenty-one billion, forty-five million, two hundred twelve thousand, four hundred fifty-three".