91987726 has 16 divisors (see below), whose sum is σ = 144852480. Its totient is φ = 43754040.

The previous prime is 91987711. The next prime is 91987729. The reversal of 91987726 is 62778919.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 91987726.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91987729) 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 7 ways as a sum of consecutive naturals, for example, 8916 + ... + 16231.

It is an arithmetic number, because the mean of its divisors is an integer number (9053280).

Almost surely, 2^91987726 is an apocalyptic number.

91987726 is a deficient number, since it is larger than the sum of its proper divisors (52864754).

91987726 is a wasteful number, since it uses less digits than its factorization.

91987726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25239.

The product of its digits is 381024, while the sum is 49.

The square root of 91987726 is about 9591.0231988042. The cubic root of 91987726 is about 451.4156668490.

The spelling of 91987726 in words is "ninety-one million, nine hundred eighty-seven thousand, seven hundred twenty-six".