71311440 has 80 divisors (see below), whose sum is σ = 224735616. Its totient is φ = 18700800.

The previous prime is 71311421. The next prime is 71311453. The reversal of 71311440 is 4411317.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12205 + ... + 17075.

Almost surely, 2^71311440 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 71311440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112367808).

71311440 is an abundant number, since it is smaller than the sum of its proper divisors (153424176).

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

71311440 is a wasteful number, since it uses less digits than its factorization.

71311440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4948 (or 4942 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 71311440 is about 8444.6101153339. The cubic root of 71311440 is about 414.6863454760.

Adding to 71311440 its reverse (4411317), we get a palindrome (75722757).

The spelling of 71311440 in words is "seventy-one million, three hundred eleven thousand, four hundred forty".