91555268821 has 16 divisors (see below), whose sum is σ = 98833109760. Its totient is φ = 84538667520.

The previous prime is 91555268813. The next prime is 91555268863. The reversal of 91555268821 is 12886255519.

It is a cyclic number.

It is not a de Polignac number, because 91555268821 - 2³ = 91555268813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91555268801) 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 in 15 ways as a sum of consecutive naturals, for example, 2505 + ... + 427921.

It is an arithmetic number, because the mean of its divisors is an integer number (6177069360).

Almost surely, 2^91555268821 is an apocalyptic number.

It is an amenable number.

91555268821 is a deficient number, since it is larger than the sum of its proper divisors (7277840939).

91555268821 is a wasteful number, since it uses less digits than its factorization.

91555268821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425724.

The product of its digits is 1728000, while the sum is 52.

The spelling of 91555268821 in words is "ninety-one billion, five hundred fifty-five million, two hundred sixty-eight thousand, eight hundred twenty-one".