71221201920 has 528 divisors, whose sum is σ = 273143819520. Its totient is φ = 17013964800.

The previous prime is 71221201861. The next prime is 71221201927. The reversal of 71221201920 is 2910212217.

It is a tau number, because it is divible by the number of its divisors (528).

It is not an unprimeable number, because it can be changed into a prime (71221201927) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 35987491 + ... + 35989469.

It is an arithmetic number, because the mean of its divisors is an integer number (517317840).

Almost surely, 2^71221201920 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 71221201920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136571909760).

71221201920 is an abundant number, since it is smaller than the sum of its proper divisors (201922617600).

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

71221201920 is a wasteful number, since it uses less digits than its factorization.

71221201920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2092 (or 2071 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The spelling of 71221201920 in words is "seventy-one billion, two hundred twenty-one million, two hundred one thousand, nine hundred twenty".