91887979191 has 8 divisors (see below), whose sum is σ = 126469476864. Its totient is φ = 59282567160.

The previous prime is 91887979181. The next prime is 91887979201. The reversal of 91887979191 is 19197978819.

It is an interprime number because it is at equal distance from previous prime (91887979181) and next prime (91887979201).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91887979191 - 2¹⁰ = 91887978167 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91887979111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 494021301 + ... + 494021486.

It is an arithmetic number, because the mean of its divisors is an integer number (15808684608).

Almost surely, 2^91887979191 is an apocalyptic number.

91887979191 is a deficient number, since it is larger than the sum of its proper divisors (34581497673).

91887979191 is a wasteful number, since it uses less digits than its factorization.

91887979191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 988042821.

The product of its digits is 20575296, while the sum is 69.

The spelling of 91887979191 in words is "ninety-one billion, eight hundred eighty-seven million, nine hundred seventy-nine thousand, one hundred ninety-one".