91366999621 has 16 divisors (see below), whose sum is σ = 93130428160. Its totient is φ = 89620577280.

The previous prime is 91366999583. The next prime is 91366999627. The reversal of 91366999621 is 12699966319.

It is a cyclic number.

It is not a de Polignac number, because 91366999621 - 2²⁹ = 90830128709 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91366999621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91366999627) 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, 8238346 + ... + 8249428.

It is an arithmetic number, because the mean of its divisors is an integer number (5820651760).

Almost surely, 2^91366999621 is an apocalyptic number.

It is an amenable number.

91366999621 is a deficient number, since it is larger than the sum of its proper divisors (1763428539).

91366999621 is a wasteful number, since it uses less digits than its factorization.

91366999621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11836.

The product of its digits is 8503056, while the sum is 61.

The spelling of 91366999621 in words is "ninety-one billion, three hundred sixty-six million, nine hundred ninety-nine thousand, six hundred twenty-one".