91909404 has 84 divisors (see below), whose sum is σ = 247096696. Its totient is φ = 29883168.

The previous prime is 91909387. The next prime is 91909421. The reversal of 91909404 is 40490919.

It is an interprime number because it is at equal distance from previous prime (91909387) and next prime (91909421).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 125022 + ... + 125754.

Almost surely, 2^91909404 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 91909404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123548348).

91909404 is an abundant number, since it is smaller than the sum of its proper divisors (155187292).

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

91909404 is a wasteful number, since it uses less digits than its factorization.

91909404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798 (or 781 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 91909404 is about 9586.9392404458. The cubic root of 91909404 is about 451.2875127333.

The spelling of 91909404 in words is "ninety-one million, nine hundred nine thousand, four hundred four".