31242191 has 2 divisors, whose sum is σ = 31242192. Its totient is φ = 31242190.

The previous prime is 31242179. The next prime is 31242217. The reversal of 31242191 is 19124213.

It is a weak prime.

It is an emirp because it is prime and its reverse (19124213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31242191 - 2¹⁰ = 31241167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31242091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15621095 + 15621096.

It is an arithmetic number, because the mean of its divisors is an integer number (15621096).

Almost surely, 2^31242191 is an apocalyptic number.

31242191 is a deficient number, since it is larger than the sum of its proper divisors (1).

31242191 is an equidigital number, since it uses as much as digits as its factorization.

31242191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 31242191 is about 5589.4714419165. The cubic root of 31242191 is about 314.9540236921.

The spelling of 31242191 in words is "thirty-one million, two hundred forty-two thousand, one hundred ninety-one".