91550420393 has 2 divisors, whose sum is σ = 91550420394. Its totient is φ = 91550420392.

The previous prime is 91550420359. The next prime is 91550420413. The reversal of 91550420393 is 39302405519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91550420329 + 64 = 302573^2 + 8^2 .

It is a cyclic number.

It is not a de Polignac number, because 91550420393 - 2³² = 87255453097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91550420393.

It is not a weakly prime, because it can be changed into another prime (91550420993) 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, 45775210196 + 45775210197.

It is an arithmetic number, because the mean of its divisors is an integer number (45775210197).

Almost surely, 2^91550420393 is an apocalyptic number.

It is an amenable number.

91550420393 is a deficient number, since it is larger than the sum of its proper divisors (1).

91550420393 is an equidigital number, since it uses as much as digits as its factorization.

91550420393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145800, while the sum is 41.

The spelling of 91550420393 in words is "ninety-one billion, five hundred fifty million, four hundred twenty thousand, three hundred ninety-three".