91511940 has 96 divisors (see below), whose sum is σ = 287997696. Its totient is φ = 21542400.

The previous prime is 91511939. The next prime is 91511947. The reversal of 91511940 is 4911519.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 91511898 and 91511907.

It is not an unprimeable number, because it can be changed into a prime (91511947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15390 + ... + 20490.

It is an arithmetic number, because the mean of its divisors is an integer number (2999976).

Almost surely, 2^91511940 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 91511940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143998848).

91511940 is an abundant number, since it is smaller than the sum of its proper divisors (196485756).

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

91511940 is a wasteful number, since it uses less digits than its factorization.

91511940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5149 (or 5147 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 91511940 is about 9566.1873282933. The cubic root of 91511940 is about 450.6360388582.

The spelling of 91511940 in words is "ninety-one million, five hundred eleven thousand, nine hundred forty".