91668920837 has 64 divisors (see below), whose sum is σ = 110811939840. Its totient is φ = 75026497536.

The previous prime is 91668920809. The next prime is 91668920851. The reversal of 91668920837 is 73802986619.

It is a cyclic number.

It is not a de Polignac number, because 91668920837 - 2²² = 91664726533 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 (91668920887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 37277714 + ... + 37280172.

It is an arithmetic number, because the mean of its divisors is an integer number (1731436560).

Almost surely, 2^91668920837 is an apocalyptic number.

91668920837 is a gapful number since it is divisible by the number (97) formed by its first and last digit.

It is an amenable number.

91668920837 is a deficient number, since it is larger than the sum of its proper divisors (19143019003).

91668920837 is a wasteful number, since it uses less digits than its factorization.

91668920837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2670.

The product of its (nonzero) digits is 7838208, while the sum is 59.

The spelling of 91668920837 in words is "ninety-one billion, six hundred sixty-eight million, nine hundred twenty thousand, eight hundred thirty-seven".