31204009 has 2 divisors, whose sum is σ = 31204010. Its totient is φ = 31204008.

The previous prime is 31204007. The next prime is 31204013. The reversal of 31204009 is 90040213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27594009 + 3610000 = 5253^2 + 1900^2 .

It is a cyclic number.

It is not a de Polignac number, because 31204009 - 2¹ = 31204007 is a prime.

Together with 31204007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31204007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15602004 + 15602005.

It is an arithmetic number, because the mean of its divisors is an integer number (15602005).

Almost surely, 2^31204009 is an apocalyptic number.

It is an amenable number.

31204009 is a deficient number, since it is larger than the sum of its proper divisors (1).

31204009 is an equidigital number, since it uses as much as digits as its factorization.

31204009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 31204009 is about 5586.0548690467. The cubic root of 31204009 is about 314.8256665313.

The spelling of 31204009 in words is "thirty-one million, two hundred four thousand, nine".