91878886431 has 12 divisors (see below), whose sum is σ = 132738056880. Its totient is φ = 61241463360.

The previous prime is 91878886423. The next prime is 91878886447. The reversal of 91878886431 is 13468887819.

It is not a de Polignac number, because 91878886431 - 2³ = 91878886423 is a prime.

It is a super-2 number, since 2×91878886431² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91878885431) 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 11 ways as a sum of consecutive naturals, for example, 874851 + ... + 974228.

It is an arithmetic number, because the mean of its divisors is an integer number (11061504740).

Almost surely, 2^91878886431 is an apocalyptic number.

91878886431 is a deficient number, since it is larger than the sum of its proper divisors (40859170449).

91878886431 is a wasteful number, since it uses less digits than its factorization.

91878886431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854606 (or 1854603 counting only the distinct ones).

The product of its digits is 18579456, while the sum is 63.

The spelling of 91878886431 in words is "ninety-one billion, eight hundred seventy-eight million, eight hundred eighty-six thousand, four hundred thirty-one".