91537920 has 240 divisors, whose sum is σ = 330347160. Its totient is φ = 23396352.

The previous prime is 91537913. The next prime is 91537921. The reversal of 91537920 is 2973519.

It can be written as a sum of positive squares in 4 ways, for example, as 77158656 + 14379264 = 8784^2 + 3792^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (91537921) 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, 668092 + ... + 668228.

Almost surely, 2^91537920 is an apocalyptic number.

91537920 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91537920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165173580).

91537920 is an abundant number, since it is smaller than the sum of its proper divisors (238809240).

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

91537920 is a wasteful number, since it uses less digits than its factorization.

91537920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 36.

The square root of 91537920 is about 9567.5451396897. The cubic root of 91537920 is about 450.6786796202.

The spelling of 91537920 in words is "ninety-one million, five hundred thirty-seven thousand, nine hundred twenty".