71947664 has 20 divisors (see below), whose sum is σ = 139949004. Its totient is φ = 35831808.

The previous prime is 71947649. The next prime is 71947669. The reversal of 71947664 is 46674917.

It can be written as a sum of positive squares in 2 ways, for example, as 33408400 + 38539264 = 5780^2 + 6208^2 .

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (71947669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4637 + ... + 12860.

Almost surely, 2^71947664 is an apocalyptic number.

It is an amenable number.

71947664 is a deficient number, since it is larger than the sum of its proper divisors (68001340).

71947664 is a wasteful number, since it uses less digits than its factorization.

71947664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17762 (or 17756 counting only the distinct ones).

The product of its digits is 254016, while the sum is 44.

The square root of 71947664 is about 8482.1968852415. The cubic root of 71947664 is about 415.9159408559.

The spelling of 71947664 in words is "seventy-one million, nine hundred forty-seven thousand, six hundred sixty-four".