91021536 has 96 divisors (see below), whose sum is σ = 281141280. Its totient is φ = 28551168.

The previous prime is 91021531. The next prime is 91021537. The reversal of 91021536 is 63512019.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91021531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11590 + ... + 17786.

It is an arithmetic number, because the mean of its divisors is an integer number (2928555).

Almost surely, 2^91021536 is an apocalyptic number.

91021536 is a gapful number since it is divisible by the number (96) 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 91021536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140570640).

91021536 is an abundant number, since it is smaller than the sum of its proper divisors (190119744).

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

91021536 is a wasteful number, since it uses less digits than its factorization.

91021536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6233 (or 6219 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 91021536 is about 9540.5207405047. The cubic root of 91021536 is about 449.8296243907.

The spelling of 91021536 in words is "ninety-one million, twenty-one thousand, five hundred thirty-six".