91973947 has 16 divisors (see below), whose sum is σ = 103850208. Its totient is φ = 80881920.

The previous prime is 91973923. The next prime is 91973951. The reversal of 91973947 is 74937919.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 91973947 - 2²³ = 83585339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91973947.

It is not an unprimeable number, because it can be changed into a prime (91973347) 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, 20913 + ... + 24925.

It is an arithmetic number, because the mean of its divisors is an integer number (6490638).

Almost surely, 2^91973947 is an apocalyptic number.

91973947 is a deficient number, since it is larger than the sum of its proper divisors (11876261).

91973947 is a wasteful number, since it uses less digits than its factorization.

91973947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4110.

The product of its digits is 428652, while the sum is 49.

The square root of 91973947 is about 9590.3048439557. The cubic root of 91973947 is about 451.3931262800.

The spelling of 91973947 in words is "ninety-one million, nine hundred seventy-three thousand, nine hundred forty-seven".