91612221563 has 2 divisors, whose sum is σ = 91612221564. Its totient is φ = 91612221562.

The previous prime is 91612221523. The next prime is 91612221577. The reversal of 91612221563 is 36512221619.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91612221563 - 2⁶ = 91612221499 is a prime.

It is not a weakly prime, because it can be changed into another prime (91612221523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45806110781 + 45806110782.

It is an arithmetic number, because the mean of its divisors is an integer number (45806110782).

Almost surely, 2^91612221563 is an apocalyptic number.

91612221563 is a deficient number, since it is larger than the sum of its proper divisors (1).

91612221563 is an equidigital number, since it uses as much as digits as its factorization.

91612221563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 38.

The spelling of 91612221563 in words is "ninety-one billion, six hundred twelve million, two hundred twenty-one thousand, five hundred sixty-three".