71851440 has 80 divisors (see below), whose sum is σ = 225485568. Its totient is φ = 18924288.

The previous prime is 71851427. The next prime is 71851441. The reversal of 71851440 is 4415817.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 71851398 and 71851407.

It is not an unprimeable number, because it can be changed into a prime (71851441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18117 + ... + 21723.

Almost surely, 2^71851440 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 71851440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112742784).

71851440 is an abundant number, since it is smaller than the sum of its proper divisors (153634128).

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

71851440 is a wasteful number, since it uses less digits than its factorization.

71851440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3706 (or 3700 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 71851440 is about 8476.5228720272. The cubic root of 71851440 is about 415.7304405068.

The spelling of 71851440 in words is "seventy-one million, eight hundred fifty-one thousand, four hundred forty".