71144240 has 40 divisors (see below), whose sum is σ = 167519040. Its totient is φ = 28094976.

The previous prime is 71144233. The next prime is 71144243. The reversal of 71144240 is 4244117.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (71144243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 692 + ... + 11948.

It is an arithmetic number, because the mean of its divisors is an integer number (4187976).

Almost surely, 2^71144240 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 71144240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83759520).

71144240 is an abundant number, since it is smaller than the sum of its proper divisors (96374800).

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

71144240 is a wasteful number, since it uses less digits than its factorization.

71144240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11349 (or 11343 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 71144240 is about 8434.7044998625. The cubic root of 71144240 is about 414.3619944474.

Adding to 71144240 its reverse (4244117), we get a palindrome (75388357).

The spelling of 71144240 in words is "seventy-one million, one hundred forty-four thousand, two hundred forty".