91321952287505 has 16 divisors (see below), whose sum is σ = 110827595682000. Its totient is φ = 72230207216640.

The previous prime is 91321952287439. The next prime is 91321952287507. The reversal of 91321952287505 is 50578225912319.

It is a Cunningham number, because it is equal to 9556252²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 19004089359424 + 72317862928081 = 4359368^2 + 8503991^2 .

It is not a de Polignac number, because 91321952287505 - 2¹² = 91321952283409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91321952287507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4242116 + ... + 14164725.

It is an arithmetic number, because the mean of its divisors is an integer number (6926724730125).

Almost surely, 2^{91321952287505} is an apocalyptic number.

It is an amenable number.

91321952287505 is a deficient number, since it is larger than the sum of its proper divisors (19505643394495).

91321952287505 is a wasteful number, since it uses less digits than its factorization.

91321952287505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18418084.

The product of its (nonzero) digits is 13608000, while the sum is 59.

The spelling of 91321952287505 in words is "ninety-one trillion, three hundred twenty-one billion, nine hundred fifty-two million, two hundred eighty-seven thousand, five hundred five".