21613321063 has 4 divisors (see below), whose sum is σ = 21613853560. Its totient is φ = 21612788568.

The previous prime is 21613321049. The next prime is 21613321073. The reversal of 21613321063 is 36012331612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21613321063 - 2²¹ = 21611223911 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 (21613321013) 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, 199845 + ... + 288382.

It is an arithmetic number, because the mean of its divisors is an integer number (5403463390).

Almost surely, 2^21613321063 is an apocalyptic number.

21613321063 is a deficient number, since it is larger than the sum of its proper divisors (532497).

21613321063 is an equidigital number, since it uses as much as digits as its factorization.

21613321063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532496.

The product of its (nonzero) digits is 3888, while the sum is 28.

Adding to 21613321063 its reverse (36012331612), we get a palindrome (57625652675).

The spelling of 21613321063 in words is "twenty-one billion, six hundred thirteen million, three hundred twenty-one thousand, sixty-three".