21653559089 has 4 divisors (see below), whose sum is σ = 21656399856. Its totient is φ = 21650718324.

The previous prime is 21653559061. The next prime is 21653559091. The reversal of 21653559089 is 98095535612.

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 21653559089 - 2¹⁶ = 21653493553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21653559089.

It is not an unprimeable number, because it can be changed into a prime (21653559689) 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, 1408919 + ... + 1424204.

It is an arithmetic number, because the mean of its divisors is an integer number (5414099964).

Almost surely, 2^21653559089 is an apocalyptic number.

It is an amenable number.

21653559089 is a deficient number, since it is larger than the sum of its proper divisors (2840767).

21653559089 is an equidigital number, since it uses as much as digits as its factorization.

21653559089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2840766.

The product of its (nonzero) digits is 2916000, while the sum is 53.

The spelling of 21653559089 in words is "twenty-one billion, six hundred fifty-three million, five hundred fifty-nine thousand, eighty-nine".