71511680 has 64 divisors (see below), whose sum is σ = 176898600. Its totient is φ = 27611136.

The previous prime is 71511679. The next prime is 71511683. The reversal of 71511680 is 8611517.

It can be written as a sum of positive squares in 4 ways, for example, as 70694464 + 817216 = 8408^2 + 904^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×71511680² = 10227840752844800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (71511683) 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, 16634 + ... + 20486.

Almost surely, 2^71511680 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 71511680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88449300).

71511680 is an abundant number, since it is smaller than the sum of its proper divisors (105386920).

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

71511680 is a wasteful number, since it uses less digits than its factorization.

71511680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3901 (or 3889 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 29.

The square root of 71511680 is about 8456.4578873190. The cubic root of 71511680 is about 415.0741242736.

The spelling of 71511680 in words is "seventy-one million, five hundred eleven thousand, six hundred eighty".