71816640 has 112 divisors (see below), whose sum is σ = 260616192. Its totient is φ = 16413696.

The previous prime is 71816639. The next prime is 71816669. The reversal of 71816640 is 4661817.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377 + ... + 12063.

Almost surely, 2^71816640 is an apocalyptic number.

71816640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71816640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130308096).

71816640 is an abundant number, since it is smaller than the sum of its proper divisors (188799552).

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

71816640 is a wasteful number, since it uses less digits than its factorization.

71816640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10714 (or 10704 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 71816640 is about 8474.4698949256. The cubic root of 71816640 is about 415.6633123896.

The spelling of 71816640 in words is "seventy-one million, eight hundred sixteen thousand, six hundred forty".