71121240 has 144 divisors (see below), whose sum is σ = 240907680. Its totient is φ = 18895680.

The previous prime is 71121233. The next prime is 71121241. The reversal of 71121240 is 4212117.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71121241) 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 35 ways as a sum of consecutive naturals, for example, 262305 + ... + 262575.

It is an arithmetic number, because the mean of its divisors is an integer number (1672970).

Almost surely, 2^71121240 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 71121240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120453840).

71121240 is an abundant number, since it is smaller than the sum of its proper divisors (169786440).

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

71121240 is an equidigital number, since it uses as much as digits as its factorization.

71121240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 281 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 71121240 is about 8433.3409749636. The cubic root of 71121240 is about 414.3173370347.

Adding to 71121240 its reverse (4212117), we get a palindrome (75333357).

The spelling of 71121240 in words is "seventy-one million, one hundred twenty-one thousand, two hundred forty".