91038840 has 64 divisors (see below), whose sum is σ = 277616160. Its totient is φ = 23877120.

The previous prime is 91038839. The next prime is 91038841. The reversal of 91038840 is 4883019.

It is an interprime number because it is at equal distance from previous prime (91038839) and next prime (91038841).

It is a super-3 number, since 3×91038840³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91038841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1102 + ... + 13538.

Almost surely, 2^91038840 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 91038840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138808080).

91038840 is an abundant number, since it is smaller than the sum of its proper divisors (186577320).

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

91038840 is a wasteful number, since it uses less digits than its factorization.

91038840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12512 (or 12508 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 91038840 is about 9541.4275661454. The cubic root of 91038840 is about 449.8581281161.

The spelling of 91038840 in words is "ninety-one million, thirty-eight thousand, eight hundred forty".