91409544 has 144 divisors (see below), whose sum is σ = 275857920. Its totient is φ = 27287040.

The previous prime is 91409533. The next prime is 91409579. The reversal of 91409544 is 44590419.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 91409499 and 91409508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 478489 + ... + 478679.

It is an arithmetic number, because the mean of its divisors is an integer number (1915680).

Almost surely, 2^91409544 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 91409544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137928960).

91409544 is an abundant number, since it is smaller than the sum of its proper divisors (184448376).

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

91409544 is a wasteful number, since it uses less digits than its factorization.

91409544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260 (or 236 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 91409544 is about 9560.8338548476. The cubic root of 91409544 is about 450.4678985076.

The spelling of 91409544 in words is "ninety-one million, four hundred nine thousand, five hundred forty-four".