21338809001 has 4 divisors (see below), whose sum is σ = 21688625604. Its totient is φ = 20988992400.

The previous prime is 21338808991. The next prime is 21338809021. The reversal of 21338809001 is 10090883312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 817960000 + 20520849001 = 28600^2 + 143251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21338809001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21338809021) 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, 174908210 + ... + 174908331.

It is an arithmetic number, because the mean of its divisors is an integer number (5422156401).

Almost surely, 2^21338809001 is an apocalyptic number.

It is an amenable number.

21338809001 is a deficient number, since it is larger than the sum of its proper divisors (349816603).

21338809001 is an equidigital number, since it uses as much as digits as its factorization.

21338809001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349816602.

The product of its (nonzero) digits is 10368, while the sum is 35.

The spelling of 21338809001 in words is "twenty-one billion, three hundred thirty-eight million, eight hundred nine thousand, one".