91834872557 has 2 divisors, whose sum is σ = 91834872558. Its totient is φ = 91834872556.

The previous prime is 91834872553. The next prime is 91834872587. The reversal of 91834872557 is 75527843819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90036603721 + 1798268836 = 300061^2 + 42406^2 .

It is a cyclic number.

It is not a de Polignac number, because 91834872557 - 2² = 91834872553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91834872496 and 91834872505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91834872553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45917436278 + 45917436279.

It is an arithmetic number, because the mean of its divisors is an integer number (45917436279).

Almost surely, 2^91834872557 is an apocalyptic number.

It is an amenable number.

91834872557 is a deficient number, since it is larger than the sum of its proper divisors (1).

91834872557 is an equidigital number, since it uses as much as digits as its factorization.

91834872557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16934400, while the sum is 59.

The spelling of 91834872557 in words is "ninety-one billion, eight hundred thirty-four million, eight hundred seventy-two thousand, five hundred fifty-seven".