99999931387 has 2 divisors, whose sum is σ = 99999931388. Its totient is φ = 99999931386.

The previous prime is 99999931379. The next prime is 99999931403. The reversal of 99999931387 is 78313999999.

It is a weak prime.

It is an emirp because it is prime and its reverse (78313999999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99999931387 - 2³ = 99999931379 is a prime.

It is not a weakly prime, because it can be changed into another prime (99999931307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999965693 + 49999965694.

It is an arithmetic number, because the mean of its divisors is an integer number (49999965694).

Almost surely, 2^99999931387 is an apocalyptic number.

99999931387 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999931387 is an equidigital number, since it uses as much as digits as its factorization.

99999931387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 267846264, while the sum is 76.

The spelling of 99999931387 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred thirty-one thousand, three hundred eighty-seven".