91140140 has 48 divisors (see below), whose sum is σ = 235566912. Its totient is φ = 28843776.

The previous prime is 91140121. The next prime is 91140143. The reversal of 91140140 is 4104119.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (91140143) 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 15 ways as a sum of consecutive naturals, for example, 23219 + ... + 26858.

It is an arithmetic number, because the mean of its divisors is an integer number (4907644).

Almost surely, 2^91140140 is an apocalyptic number.

It is an amenable number.

91140140 is an abundant number, since it is smaller than the sum of its proper divisors (144426772).

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

91140140 is a wasteful number, since it uses less digits than its factorization.

91140140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50106 (or 50104 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 91140140 is about 9546.7345202430. The cubic root of 91140140 is about 450.0249204306.

Adding to 91140140 its reverse (4104119), we get a palindrome (95244259).

The spelling of 91140140 in words is "ninety-one million, one hundred forty thousand, one hundred forty".