21004304453 has 6 divisors (see below), whose sum is σ = 23087376102. Its totient is φ = 19094822120.

The previous prime is 21004304429. The next prime is 21004304459. The reversal of 21004304453 is 35440340012.

It can be written as a sum of positive squares in only one way, i.e., 18312043684 + 2692260769 = 135322^2 + 51887^2 .

It is not a de Polignac number, because 21004304453 - 2¹⁰ = 21004303429 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 (21004304459) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86794526 + ... + 86794767.

It is an arithmetic number, because the mean of its divisors is an integer number (3847896017).

Almost surely, 2^21004304453 is an apocalyptic number.

It is an amenable number.

21004304453 is a deficient number, since it is larger than the sum of its proper divisors (2083071649).

21004304453 is a wasteful number, since it uses less digits than its factorization.

21004304453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173589315 (or 173589304 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 21004304453 its reverse (35440340012), we get a palindrome (56444644465).

The spelling of 21004304453 in words is "twenty-one billion, four million, three hundred four thousand, four hundred fifty-three".