91021320961518 has 32 divisors (see below), whose sum is σ = 182718390097152. Its totient is φ = 30227848616000.

The previous prime is 91021320961469. The next prime is 91021320961541. The reversal of 91021320961518 is 81516902312019.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6924505 + ... + 15165467.

It is an arithmetic number, because the mean of its divisors is an integer number (5709949690536).

Almost surely, 2^{91021320961518} is an apocalyptic number.

91021320961518 is an abundant number, since it is smaller than the sum of its proper divisors (91697069135634).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91021320961518 is a wasteful number, since it uses less digits than its factorization.

91021320961518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8247800.

The product of its (nonzero) digits is 233280, while the sum is 48.

The spelling of 91021320961518 in words is "ninety-one trillion, twenty-one billion, three hundred twenty million, nine hundred sixty-one thousand, five hundred eighteen".