91917408 has 144 divisors (see below), whose sum is σ = 273088368. Its totient is φ = 27033600.

The previous prime is 91917401. The next prime is 91917409. The reversal of 91917408 is 80471919.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91917401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 476160 + ... + 476352.

It is an arithmetic number, because the mean of its divisors is an integer number (1896447).

Almost surely, 2^91917408 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 91917408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136544184).

91917408 is an abundant number, since it is smaller than the sum of its proper divisors (181170960).

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

91917408 is a wasteful number, since it uses less digits than its factorization.

91917408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 91917408 is about 9587.3566742872. The cubic root of 91917408 is about 451.3006125913.

The spelling of 91917408 in words is "ninety-one million, nine hundred seventeen thousand, four hundred eight".