31271491 has 2 divisors, whose sum is σ = 31271492. Its totient is φ = 31271490.

The previous prime is 31271441. The next prime is 31271501. The reversal of 31271491 is 19417213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31271491 - 2¹⁵ = 31238723 is a prime.

It is a super-2 number, since 2×31271491² = 1955812298726162, which contains 22 as substring.

It is equal to p_1931608 and since 31271491 and 1931608 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (31271441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15635745 + 15635746.

It is an arithmetic number, because the mean of its divisors is an integer number (15635746).

Almost surely, 2^31271491 is an apocalyptic number.

31271491 is a deficient number, since it is larger than the sum of its proper divisors (1).

31271491 is an equidigital number, since it uses as much as digits as its factorization.

31271491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 28.

The square root of 31271491 is about 5592.0918268569. The cubic root of 31271491 is about 315.0524511633.

The spelling of 31271491 in words is "thirty-one million, two hundred seventy-one thousand, four hundred ninety-one".