71987636 has 48 divisors (see below), whose sum is σ = 149681280. Its totient is φ = 29652480.

The previous prime is 71987593. The next prime is 71987651. The reversal of 71987636 is 63678917.

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, 83375 + ... + 84233.

It is an arithmetic number, because the mean of its divisors is an integer number (3118360).

Almost surely, 2^71987636 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 71987636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74840640).

71987636 is an abundant number, since it is smaller than the sum of its proper divisors (77693644).

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

71987636 is a wasteful number, since it uses less digits than its factorization.

71987636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984 (or 982 counting only the distinct ones).

The product of its digits is 381024, while the sum is 47.

The square root of 71987636 is about 8484.5527872717. The cubic root of 71987636 is about 415.9929501394.

The spelling of 71987636 in words is "seventy-one million, nine hundred eighty-seven thousand, six hundred thirty-six".