71959666 has 4 divisors (see below), whose sum is σ = 107939502. Its totient is φ = 35979832.

The previous prime is 71959619. The next prime is 71959717. The reversal of 71959666 is 66695917.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 48233025 + 23726641 = 6945^2 + 4871^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17989915 + ... + 17989918.

Almost surely, 2^71959666 is an apocalyptic number.

71959666 is a deficient number, since it is larger than the sum of its proper divisors (35979836).

71959666 is a wasteful number, since it uses less digits than its factorization.

71959666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35979835.

The product of its digits is 612360, while the sum is 49.

The square root of 71959666 is about 8482.9043375485. The cubic root of 71959666 is about 415.9390666731.

It can be divided in two parts, 7195 and 9666, that added together give a palindrome (16861).

The spelling of 71959666 in words is "seventy-one million, nine hundred fifty-nine thousand, six hundred sixty-six".