91863728191 has 2 divisors, whose sum is σ = 91863728192. Its totient is φ = 91863728190.

The previous prime is 91863728179. The next prime is 91863728221. The reversal of 91863728191 is 19182736819.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91863728191 - 2¹³ = 91863719999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91863720191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45931864095 + 45931864096.

It is an arithmetic number, because the mean of its divisors is an integer number (45931864096).

Almost surely, 2^91863728191 is an apocalyptic number.

91863728191 is a deficient number, since it is larger than the sum of its proper divisors (1).

91863728191 is an equidigital number, since it uses as much as digits as its factorization.

91863728191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 55.

The spelling of 91863728191 in words is "ninety-one billion, eight hundred sixty-three million, seven hundred twenty-eight thousand, one hundred ninety-one".