91973791 has 16 divisors (see below), whose sum is σ = 119859264. Its totient is φ = 68488704.

The previous prime is 91973789. The next prime is 91973801. The reversal of 91973791 is 19737919.

91973791 = 319² + 320² + ... + 675².

It is a cyclic number.

It is not a de Polignac number, because 91973791 - 2¹ = 91973789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91973191) 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 15 ways as a sum of consecutive naturals, for example, 28180 + ... + 31273.

It is an arithmetic number, because the mean of its divisors is an integer number (7491204).

Almost surely, 2^91973791 is an apocalyptic number.

91973791 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

91973791 is a deficient number, since it is larger than the sum of its proper divisors (27885473).

91973791 is a wasteful number, since it uses less digits than its factorization.

91973791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59490.

The product of its digits is 107163, while the sum is 46.

The square root of 91973791 is about 9590.2967107384. The cubic root of 91973791 is about 451.3928710723.

The spelling of 91973791 in words is "ninety-one million, nine hundred seventy-three thousand, seven hundred ninety-one".