91673440 has 48 divisors (see below), whose sum is σ = 217455840. Its totient is φ = 36520960.

The previous prime is 91673431. The next prime is 91673441. The reversal of 91673440 is 4437619.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 91673396 and 91673405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91673441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43941 + ... + 45979.

It is an arithmetic number, because the mean of its divisors is an integer number (4530330).

Almost surely, 2^91673440 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 91673440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108727920).

91673440 is an abundant number, since it is smaller than the sum of its proper divisors (125782400).

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

91673440 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (91673439) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (2327).

91673440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2335 (or 2327 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 91673440 is about 9574.6247968262. The cubic root of 91673440 is about 450.9009767799.

The spelling of 91673440 in words is "ninety-one million, six hundred seventy-three thousand, four hundred forty".