31213000009 has 4 divisors (see below), whose sum is σ = 31216625860. Its totient is φ = 31209374160.

The previous prime is 31212999971. The next prime is 31213000031. The reversal of 31213000009 is 90000031213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90000031213 = 11887 ⋅7571299.

It can be written as a sum of positive squares in 2 ways, for example, as 8747486784 + 22465513225 = 93528^2 + 149885^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213000009 - 2¹¹ = 31212997961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31213000009.

It is not an unprimeable number, because it can be changed into a prime (31213000079) 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, 1799982 + ... + 1817239.

It is an arithmetic number, because the mean of its divisors is an integer number (7804156465).

Almost surely, 2^31213000009 is an apocalyptic number.

It is an amenable number.

31213000009 is a deficient number, since it is larger than the sum of its proper divisors (3625851).

31213000009 is an equidigital number, since it uses as much as digits as its factorization.

31213000009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3625850.

The product of its (nonzero) digits is 162, while the sum is 19.

The spelling of 31213000009 in words is "thirty-one billion, two hundred thirteen million, nine", and thus it is an aban number.