71987634 has 12 divisors (see below), whose sum is σ = 155973246. Its totient is φ = 23995872.

The previous prime is 71987593. The next prime is 71987651. The reversal of 71987634 is 43678917.

71987634 is a `hidden beast` number, since 7 + 1 + 9 + 8 + 7 + 634 = 666.

It can be written as a sum of positive squares in only one way, i.e., 65561409 + 6426225 = 8097^2 + 2535^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 71987634.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1999639 + ... + 1999674.

Almost surely, 2^71987634 is an apocalyptic number.

71987634 is an abundant number, since it is smaller than the sum of its proper divisors (83985612).

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

71987634 is a wasteful number, since it uses less digits than its factorization.

71987634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3999321 (or 3999318 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 71987634 is about 8484.5526694105. The cubic root of 71987634 is about 415.9929462870.

The spelling of 71987634 in words is "seventy-one million, nine hundred eighty-seven thousand, six hundred thirty-four".