21664030441 has 4 divisors (see below), whose sum is σ = 22605944832. Its totient is φ = 20722116052.

The previous prime is 21664030417. The next prime is 21664030471. The reversal of 21664030441 is 14403046612.

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 21664030441 - 2¹³ = 21664022249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21664030471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 470957161 + ... + 470957206.

It is an arithmetic number, because the mean of its divisors is an integer number (5651486208).

Almost surely, 2^21664030441 is an apocalyptic number.

It is an amenable number.

21664030441 is a deficient number, since it is larger than the sum of its proper divisors (941914391).

21664030441 is an equidigital number, since it uses as much as digits as its factorization.

21664030441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 941914390.

The product of its (nonzero) digits is 13824, while the sum is 31.

The spelling of 21664030441 in words is "twenty-one billion, six hundred sixty-four million, thirty thousand, four hundred forty-one".