21611459808953 has 4 divisors (see below), whose sum is σ = 24698811210240. Its totient is φ = 18524108407668.

The previous prime is 21611459808937. The next prime is 21611459808959. The reversal of 21611459808953 is 35980895411612.

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 21611459808953 - 2⁴ = 21611459808937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21611459808959) 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, 1543675700633 + ... + 1543675700646.

It is an arithmetic number, because the mean of its divisors is an integer number (6174702802560).

Almost surely, 2^{21611459808953} is an apocalyptic number.

It is an amenable number.

21611459808953 is a deficient number, since it is larger than the sum of its proper divisors (3087351401287).

21611459808953 is an equidigital number, since it uses as much as digits as its factorization.

21611459808953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3087351401286.

The product of its (nonzero) digits is 18662400, while the sum is 62.

The spelling of 21611459808953 in words is "twenty-one trillion, six hundred eleven billion, four hundred fifty-nine million, eight hundred eight thousand, nine hundred fifty-three".