71521317220 has 24 divisors (see below), whose sum is σ = 150684012864. Its totient is φ = 28515337056.

The previous prime is 71521317173. The next prime is 71521317223. The reversal of 71521317220 is 2271312517.

It is not an unprimeable number, because it can be changed into a prime (71521317223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5818072 + ... + 5830351.

It is an arithmetic number, because the mean of its divisors is an integer number (6278500536).

Almost surely, 2^71521317220 is an apocalyptic number.

It is an amenable number.

71521317220 is an abundant number, since it is smaller than the sum of its proper divisors (79162695644).

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

71521317220 is a wasteful number, since it uses less digits than its factorization.

71521317220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11648739 (or 11648737 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 31.

Adding to 71521317220 its reverse (2271312517), we get a palindrome (73792629737).

The spelling of 71521317220 in words is "seventy-one billion, five hundred twenty-one million, three hundred seventeen thousand, two hundred twenty".