91917864 has 24 divisors (see below), whose sum is σ = 248944410. Its totient is φ = 30639264.

The previous prime is 91917851. The next prime is 91917869. The reversal of 91917864 is 46871919.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 91355364 + 562500 = 9558^2 + 750^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (91917869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 638247 + ... + 638390.

Almost surely, 2^91917864 is an apocalyptic number.

It is an amenable number.

91917864 is an abundant number, since it is smaller than the sum of its proper divisors (157026546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91917864 is a wasteful number, since it uses less digits than its factorization.

91917864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276649 (or 1276642 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 91917864 is about 9587.3804555781. The cubic root of 91917864 is about 451.3013588871.

The spelling of 91917864 in words is "ninety-one million, nine hundred seventeen thousand, eight hundred sixty-four".