91389186739 has 2 divisors, whose sum is σ = 91389186740. Its totient is φ = 91389186738.

The previous prime is 91389186661. The next prime is 91389186793. The reversal of 91389186739 is 93768198319.

Together with next prime (91389186793) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91389186739 - 2²⁵ = 91355632307 is a prime.

It is not a weakly prime, because it can be changed into another prime (91389286739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45694593369 + 45694593370.

It is an arithmetic number, because the mean of its divisors is an integer number (45694593370).

Almost surely, 2^91389186739 is an apocalyptic number.

91389186739 is a deficient number, since it is larger than the sum of its proper divisors (1).

91389186739 is an equidigital number, since it uses as much as digits as its factorization.

91389186739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17635968, while the sum is 64.

The spelling of 91389186739 in words is "ninety-one billion, three hundred eighty-nine million, one hundred eighty-six thousand, seven hundred thirty-nine".