71688447640 has 32 divisors (see below), whose sum is σ = 164730905280. Its totient is φ = 28065263872.

The previous prime is 71688447631. The next prime is 71688447641. The reversal of 71688447640 is 4674488617.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71688447641) 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, 19064197 + ... + 19067956.

It is an arithmetic number, because the mean of its divisors is an integer number (5147840790).

Almost surely, 2^71688447640 is an apocalyptic number.

It is an amenable number.

71688447640 is an abundant number, since it is smaller than the sum of its proper divisors (93042457640).

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

71688447640 is a wasteful number, since it uses less digits than its factorization.

71688447640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38132211 (or 38132207 counting only the distinct ones).

The product of its (nonzero) digits is 7225344, while the sum is 55.

The spelling of 71688447640 in words is "seventy-one billion, six hundred eighty-eight million, four hundred forty-seven thousand, six hundred forty".