31969213 has 2 divisors, whose sum is σ = 31969214. Its totient is φ = 31969212.

The previous prime is 31969183. The next prime is 31969237. The reversal of 31969213 is 31296913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28965924 + 3003289 = 5382^2 + 1733^2 .

It is an emirp because it is prime and its reverse (31296913) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31969213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31960213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15984606 + 15984607.

It is an arithmetic number, because the mean of its divisors is an integer number (15984607).

Almost surely, 2^31969213 is an apocalyptic number.

It is an amenable number.

31969213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31969213 is an equidigital number, since it uses as much as digits as its factorization.

31969213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 34.

The square root of 31969213 is about 5654.1323826030. The cubic root of 31969213 is about 317.3783624822.

The spelling of 31969213 in words is "thirty-one million, nine hundred sixty-nine thousand, two hundred thirteen".