31121197 has 2 divisors, whose sum is σ = 31121198. Its totient is φ = 31121196.

The previous prime is 31121177. The next prime is 31121249. The reversal of 31121197 is 79112113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16597476 + 14523721 = 4074^2 + 3811^2 .

It is an emirp because it is prime and its reverse (79112113) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31121197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31121137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560598 + 15560599.

It is an arithmetic number, because the mean of its divisors is an integer number (15560599).

Almost surely, 2^31121197 is an apocalyptic number.

It is an amenable number.

31121197 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121197 is an equidigital number, since it uses as much as digits as its factorization.

31121197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 25.

The square root of 31121197 is about 5578.6375576838. The cubic root of 31121197 is about 314.5469155899.

The spelling of 31121197 in words is "thirty-one million, one hundred twenty-one thousand, one hundred ninety-seven".