91019872513 has 2 divisors, whose sum is σ = 91019872514. Its totient is φ = 91019872512.

The previous prime is 91019872511. The next prime is 91019872543. The reversal of 91019872513 is 31527891019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88466389489 + 2553483024 = 297433^2 + 50532^2 .

It is a cyclic number.

It is not a de Polignac number, because 91019872513 - 2¹ = 91019872511 is a prime.

Together with 91019872511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91019872511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45509936256 + 45509936257.

It is an arithmetic number, because the mean of its divisors is an integer number (45509936257).

Almost surely, 2^91019872513 is an apocalyptic number.

It is an amenable number.

91019872513 is a deficient number, since it is larger than the sum of its proper divisors (1).

91019872513 is an equidigital number, since it uses as much as digits as its factorization.

91019872513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 136080, while the sum is 46.

The spelling of 91019872513 in words is "ninety-one billion, nineteen million, eight hundred seventy-two thousand, five hundred thirteen".