71581920 has 96 divisors (see below), whose sum is σ = 226927008. Its totient is φ = 18966528.

The previous prime is 71581919. The next prime is 71581931. The reversal of 71581920 is 2918517.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94182 + ... + 94938.

It is an arithmetic number, because the mean of its divisors is an integer number (2363823).

Almost surely, 2^71581920 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 71581920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113463504).

71581920 is an abundant number, since it is smaller than the sum of its proper divisors (155345088).

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

71581920 is a wasteful number, since it uses less digits than its factorization.

71581920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 71581920 is about 8460.6099070930. The cubic root of 71581920 is about 415.2099774482.

The spelling of 71581920 in words is "seventy-one million, five hundred eighty-one thousand, nine hundred twenty".