31323123209 has 4 divisors (see below), whose sum is σ = 35797855104. Its totient is φ = 26848391316.

The previous prime is 31323123193. The next prime is 31323123269. The reversal of 31323123209 is 90232132313.

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 31323123209 - 2⁴ = 31323123193 is a prime.

It is a super-2 number, since 2×31323123209² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31323123269) 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, 2237365937 + ... + 2237365950.

It is an arithmetic number, because the mean of its divisors is an integer number (8949463776).

Almost surely, 2^31323123209 is an apocalyptic number.

It is an amenable number.

31323123209 is a deficient number, since it is larger than the sum of its proper divisors (4474731895).

31323123209 is an equidigital number, since it uses as much as digits as its factorization.

31323123209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4474731894.

The product of its (nonzero) digits is 5832, while the sum is 29.

The spelling of 31323123209 in words is "thirty-one billion, three hundred twenty-three million, one hundred twenty-three thousand, two hundred nine".