71245840 has 80 divisors (see below), whose sum is σ = 171864000. Its totient is φ = 27449856.

The previous prime is 71245817. The next prime is 71245841. The reversal of 71245840 is 4854217.

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

It is not an unprimeable number, because it can be changed into a prime (71245841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 478086 + ... + 478234.

It is an arithmetic number, because the mean of its divisors is an integer number (2148300).

Almost surely, 2^71245840 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 71245840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85932000).

71245840 is an abundant number, since it is smaller than the sum of its proper divisors (100618160).

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

71245840 is a wasteful number, since it uses less digits than its factorization.

71245840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 71245840 is about 8440.7250873370. The cubic root of 71245840 is about 414.5591486331.

The spelling of 71245840 in words is "seventy-one million, two hundred forty-five thousand, eight hundred forty".