31131887 has 2 divisors, whose sum is σ = 31131888. Its totient is φ = 31131886.

The previous prime is 31131851. The next prime is 31131929. The reversal of 31131887 is 78813113.

It is a weak prime.

It is an emirp because it is prime and its reverse (78813113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31131887 - 2¹⁰ = 31130863 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31131187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15565943 + 15565944.

It is an arithmetic number, because the mean of its divisors is an integer number (15565944).

Almost surely, 2^31131887 is an apocalyptic number.

31131887 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131887 is an equidigital number, since it uses as much as digits as its factorization.

31131887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 32.

The square root of 31131887 is about 5579.5955946645. The cubic root of 31131887 is about 314.5829266469.

The spelling of 31131887 in words is "thirty-one million, one hundred thirty-one thousand, eight hundred eighty-seven".