71212221 has 12 divisors (see below), whose sum is σ = 102941280. Its totient is φ = 47438280.

The previous prime is 71212213. The next prime is 71212237. The reversal of 71212221 is 12221217.

It is a happy number.

It is not a de Polignac number, because 71212221 - 2³ = 71212213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 71212194 and 71212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71212291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14806 + ... + 19016.

It is an arithmetic number, because the mean of its divisors is an integer number (8578440).

Almost surely, 2^71212221 is an apocalyptic number.

It is an amenable number.

71212221 is a deficient number, since it is larger than the sum of its proper divisors (31729059).

71212221 is a wasteful number, since it uses less digits than its factorization.

71212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6096 (or 6093 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 71212221 is about 8438.7333765204. The cubic root of 71212221 is about 414.4939319282.

Adding to 71212221 its reverse (12221217), we get a palindrome (83433438).

The spelling of 71212221 in words is "seventy-one million, two hundred twelve thousand, two hundred twenty-one".