71721710672 has 40 divisors (see below), whose sum is σ = 141615639144. Its totient is φ = 35176054784.

The previous prime is 71721710657. The next prime is 71721710677. The reversal of 71721710672 is 27601712717.

It can be written as a sum of positive squares in 4 ways, for example, as 11492697616 + 60229013056 = 107204^2 + 245416^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71721710677) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5380688 + ... + 5394000.

Almost surely, 2^71721710672 is an apocalyptic number.

It is an amenable number.

71721710672 is a deficient number, since it is larger than the sum of its proper divisors (69893928472).

71721710672 is a wasteful number, since it uses less digits than its factorization.

71721710672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19727 (or 19721 counting only the distinct ones).

The product of its (nonzero) digits is 57624, while the sum is 41.

The spelling of 71721710672 in words is "seventy-one billion, seven hundred twenty-one million, seven hundred ten thousand, six hundred seventy-two".