21201110009 has 4 divisors (see below), whose sum is σ = 21652197504. Its totient is φ = 20750022516.

The previous prime is 21201109961. The next prime is 21201110027. The reversal of 21201110009 is 90001110212.

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 a de Polignac number, because none of the positive numbers 2^k-21201110009 is a prime.

It is a super-2 number, since 2×21201110009² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201113009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225543677 + ... + 225543770.

It is an arithmetic number, because the mean of its divisors is an integer number (5413049376).

Almost surely, 2^21201110009 is an apocalyptic number.

It is an amenable number.

21201110009 is a deficient number, since it is larger than the sum of its proper divisors (451087495).

21201110009 is an equidigital number, since it uses as much as digits as its factorization.

21201110009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451087494.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 21201110009 in words is "twenty-one billion, two hundred one million, one hundred ten thousand, nine".