91891615033 has 2 divisors, whose sum is σ = 91891615034. Its totient is φ = 91891615032.

The previous prime is 91891615003. The next prime is 91891615037. The reversal of 91891615033 is 33051619819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85874199849 + 6017415184 = 293043^2 + 77572^2 .

It is an emirp because it is prime and its reverse (33051619819) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91891615033 - 2⁵ = 91891615001 is a prime.

It is not a weakly prime, because it can be changed into another prime (91891615037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45945807516 + 45945807517.

It is an arithmetic number, because the mean of its divisors is an integer number (45945807517).

Almost surely, 2^91891615033 is an apocalyptic number.

It is an amenable number.

91891615033 is a deficient number, since it is larger than the sum of its proper divisors (1).

91891615033 is an equidigital number, since it uses as much as digits as its factorization.

91891615033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 46.

The spelling of 91891615033 in words is "ninety-one billion, eight hundred ninety-one million, six hundred fifteen thousand, thirty-three".