71668221 has 8 divisors (see below), whose sum is σ = 95630304. Its totient is φ = 47742480.

The previous prime is 71668189. The next prime is 71668231. The reversal of 71668221 is 12286617.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71668221 - 2⁵ = 71668189 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71668231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4090 + ... + 12651.

It is an arithmetic number, because the mean of its divisors is an integer number (11953788).

Almost surely, 2^71668221 is an apocalyptic number.

It is an amenable number.

71668221 is a deficient number, since it is larger than the sum of its proper divisors (23962083).

71668221 is a wasteful number, since it uses less digits than its factorization.

71668221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18171.

The product of its digits is 8064, while the sum is 33.

The square root of 71668221 is about 8465.7085350253. The cubic root of 71668221 is about 415.3767730370.

The spelling of 71668221 in words is "seventy-one million, six hundred sixty-eight thousand, two hundred twenty-one".