91005606 has 40 divisors (see below), whose sum is σ = 204880104. Its totient is φ = 30192480.

The previous prime is 91005601. The next prime is 91005613. The reversal of 91005606 is 60650019.

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

It is a self number, because there is not a number n which added to its sum of digits gives 91005606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91005601) 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 19 ways as a sum of consecutive naturals, for example, 36541 + ... + 38951.

Almost surely, 2^91005606 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91005606, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102440052).

91005606 is an abundant number, since it is smaller than the sum of its proper divisors (113874498).

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

91005606 is a wasteful number, since it uses less digits than its factorization.

91005606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2658 (or 2649 counting only the distinct ones).

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

The square root of 91005606 is about 9539.6858438840. The cubic root of 91005606 is about 449.8033807700.

It can be divided in two parts, 9100 and 5606, that added together give a triangular number (14706 = T₁₇₁).

The spelling of 91005606 in words is "ninety-one million, five thousand, six hundred six".