91172781041 has 2 divisors, whose sum is σ = 91172781042. Its totient is φ = 91172781040.

The previous prime is 91172781031. The next prime is 91172781079. The reversal of 91172781041 is 14018727119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85007233600 + 6165547441 = 291560^2 + 78521^2 .

It is a cyclic number.

It is not a de Polignac number, because 91172781041 - 2⁶ = 91172780977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 91172781041.

It is not a weakly prime, because it can be changed into another prime (91172781001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45586390520 + 45586390521.

It is an arithmetic number, because the mean of its divisors is an integer number (45586390521).

Almost surely, 2^91172781041 is an apocalyptic number.

It is an amenable number.

91172781041 is a deficient number, since it is larger than the sum of its proper divisors (1).

91172781041 is an equidigital number, since it uses as much as digits as its factorization.

91172781041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 41.

The spelling of 91172781041 in words is "ninety-one billion, one hundred seventy-two million, seven hundred eighty-one thousand, forty-one".