31131731087 has 2 divisors, whose sum is σ = 31131731088. Its totient is φ = 31131731086.

The previous prime is 31131731047. The next prime is 31131731129. The reversal of 31131731087 is 78013713113.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31131731087 - 2¹² = 31131726991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31131731027) 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, 15565865543 + 15565865544.

It is an arithmetic number, because the mean of its divisors is an integer number (15565865544).

Almost surely, 2^31131731087 is an apocalyptic number.

31131731087 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131731087 is an equidigital number, since it uses as much as digits as its factorization.

31131731087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 35.

The spelling of 31131731087 in words is "thirty-one billion, one hundred thirty-one million, seven hundred thirty-one thousand, eighty-seven".