91238548987 has 2 divisors, whose sum is σ = 91238548988. Its totient is φ = 91238548986.

The previous prime is 91238548979. The next prime is 91238548997. The reversal of 91238548987 is 78984583219.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91238548987 - 2³ = 91238548979 is a prime.

It is not a weakly prime, because it can be changed into another prime (91238548927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45619274493 + 45619274494.

It is an arithmetic number, because the mean of its divisors is an integer number (45619274494).

Almost surely, 2^91238548987 is an apocalyptic number.

91238548987 is a deficient number, since it is larger than the sum of its proper divisors (1).

91238548987 is an equidigital number, since it uses as much as digits as its factorization.

91238548987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34836480, while the sum is 64.

The spelling of 91238548987 in words is "ninety-one billion, two hundred thirty-eight million, five hundred forty-eight thousand, nine hundred eighty-seven".