91408240 has 240 divisors, whose sum is σ = 284981760. Its totient is φ = 26611200.

The previous prime is 91408223. The next prime is 91408249. The reversal of 91408240 is 4280419.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 91408199 and 91408208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91408249) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1287405 + ... + 1287475.

It is an arithmetic number, because the mean of its divisors is an integer number (1187424).

Almost surely, 2^91408240 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 91408240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142490880).

91408240 is an abundant number, since it is smaller than the sum of its proper divisors (193573520).

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

91408240 is a wasteful number, since it uses less digits than its factorization.

91408240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 91408240 is about 9560.7656597158. The cubic root of 91408240 is about 450.4657564522.

Adding to 91408240 its reverse (4280419), we get a palindrome (95688659).

The spelling of 91408240 in words is "ninety-one million, four hundred eight thousand, two hundred forty".