20131210009 has 4 divisors (see below), whose sum is σ = 20675296804. Its totient is φ = 19587123216.

The previous prime is 20131209979. The next prime is 20131210027. The reversal of 20131210009 is 90001213102.

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 7914771225 + 12216438784 = 88965^2 + 110528^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131210009 - 2¹⁹ = 20130685721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20131210079) 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, 272043342 + ... + 272043415.

It is an arithmetic number, because the mean of its divisors is an integer number (5168824201).

Almost surely, 2^20131210009 is an apocalyptic number.

It is an amenable number.

20131210009 is a deficient number, since it is larger than the sum of its proper divisors (544086795).

20131210009 is an equidigital number, since it uses as much as digits as its factorization.

20131210009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544086794.

The product of its (nonzero) digits is 108, while the sum is 19.

The spelling of 20131210009 in words is "twenty billion, one hundred thirty-one million, two hundred ten thousand, nine".