21563350451 has 8 divisors (see below), whose sum is σ = 21781503744. Its totient is φ = 21345366600.

The previous prime is 21563350441. The next prime is 21563350469. The reversal of 21563350451 is 15405336512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21563350451 - 2²⁶ = 21496241587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21563350421) 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 7 ways as a sum of consecutive naturals, for example, 221720 + ... + 303786.

It is an arithmetic number, because the mean of its divisors is an integer number (2722687968).

Almost surely, 2^21563350451 is an apocalyptic number.

21563350451 is a deficient number, since it is larger than the sum of its proper divisors (218153293).

21563350451 is a wasteful number, since it uses less digits than its factorization.

21563350451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84721.

The product of its (nonzero) digits is 54000, while the sum is 35.

Adding to 21563350451 its reverse (15405336512), we get a palindrome (36968686963).

The spelling of 21563350451 in words is "twenty-one billion, five hundred sixty-three million, three hundred fifty thousand, four hundred fifty-one".