31131020287 has 2 divisors, whose sum is σ = 31131020288. Its totient is φ = 31131020286.

The previous prime is 31131020281. The next prime is 31131020317. The reversal of 31131020287 is 78202013113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31131020287 - 2³¹ = 28983536639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31131020281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15565510143 + 15565510144.

It is an arithmetic number, because the mean of its divisors is an integer number (15565510144).

Almost surely, 2^31131020287 is an apocalyptic number.

31131020287 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131020287 is an equidigital number, since it uses as much as digits as its factorization.

31131020287 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The spelling of 31131020287 in words is "thirty-one billion, one hundred thirty-one million, twenty thousand, two hundred eighty-seven".