71639812 has 6 divisors (see below), whose sum is σ = 125369678. Its totient is φ = 35819904.

The previous prime is 71639809. The next prime is 71639837. The reversal of 71639812 is 21893617.

It can be written as a sum of positive squares in only one way, i.e., 67502656 + 4137156 = 8216^2 + 2034^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8954973 + ... + 8954980.

Almost surely, 2^71639812 is an apocalyptic number.

It is an amenable number.

71639812 is a deficient number, since it is larger than the sum of its proper divisors (53729866).

71639812 is a wasteful number, since it uses less digits than its factorization.

71639812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17909957 (or 17909955 counting only the distinct ones).

The product of its digits is 18144, while the sum is 37.

The square root of 71639812 is about 8464.0304819867. The cubic root of 71639812 is about 415.3218812122.

The spelling of 71639812 in words is "seventy-one million, six hundred thirty-nine thousand, eight hundred twelve".