31043209 has 2 divisors, whose sum is σ = 31043210. Its totient is φ = 31043208.

The previous prime is 31043197. The next prime is 31043219. The reversal of 31043209 is 90234013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30969225 + 73984 = 5565^2 + 272^2 .

It is an emirp because it is prime and its reverse (90234013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31043209 - 2⁷ = 31043081 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31043209.

It is not a weakly prime, because it can be changed into another prime (31043219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15521604 + 15521605.

It is an arithmetic number, because the mean of its divisors is an integer number (15521605).

Almost surely, 2^31043209 is an apocalyptic number.

It is an amenable number.

31043209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31043209 is an equidigital number, since it uses as much as digits as its factorization.

31043209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 31043209 is about 5571.6432943971. The cubic root of 31043209 is about 314.2839500786.

The spelling of 31043209 in words is "thirty-one million, forty-three thousand, two hundred nine".