21311332009 has 4 divisors (see below), whose sum is σ = 23248725840. Its totient is φ = 19373938180.

The previous prime is 21311331997. The next prime is 21311332057. The reversal of 21311332009 is 90023311312.

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 21311332009 - 2⁹ = 21311331497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311332069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 968696899 + ... + 968696920.

It is an arithmetic number, because the mean of its divisors is an integer number (5812181460).

Almost surely, 2^21311332009 is an apocalyptic number.

It is an amenable number.

21311332009 is a deficient number, since it is larger than the sum of its proper divisors (1937393831).

21311332009 is a wasteful number, since it uses less digits than its factorization.

21311332009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1937393830.

The product of its (nonzero) digits is 972, while the sum is 25.

The spelling of 21311332009 in words is "twenty-one billion, three hundred eleven million, three hundred thirty-two thousand, nine".