91917280 has 192 divisors, whose sum is σ = 274337280. Its totient is φ = 28329984.

The previous prime is 91917277. The next prime is 91917281. The reversal of 91917280 is 8271919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91917281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 858987 + ... + 859093.

It is an arithmetic number, because the mean of its divisors is an integer number (1428840).

Almost surely, 2^91917280 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 91917280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137168640).

91917280 is an abundant number, since it is smaller than the sum of its proper divisors (182420000).

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

91917280 is a wasteful number, since it uses less digits than its factorization.

91917280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 91917280 is about 9587.3499988266. The cubic root of 91917280 is about 451.3004031043.

It can be divided in two parts, 9191 and 7280, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 91917280 in words is "ninety-one million, nine hundred seventeen thousand, two hundred eighty".