91667840 has 128 divisors (see below), whose sum is σ = 247860000. Its totient is φ = 32112640.

The previous prime is 91667839. The next prime is 91667867. The reversal of 91667840 is 4876619.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203936 + ... + 204384.

Almost surely, 2^91667840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91667840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123930000).

91667840 is an abundant number, since it is smaller than the sum of its proper divisors (156192160).

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

91667840 is a wasteful number, since it uses less digits than its factorization.

91667840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508 (or 496 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 91667840 is about 9574.3323527022. The cubic root of 91667840 is about 450.8917952878.

The spelling of 91667840 in words is "ninety-one million, six hundred sixty-seven thousand, eight hundred forty".