71221211 has 4 divisors (see below), whose sum is σ = 75410712. Its totient is φ = 67031712.

The previous prime is 71221207. The next prime is 71221217. The reversal of 71221211 is 11212217.

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

It is a cyclic number.

It is not a de Polignac number, because 71221211 - 2² = 71221207 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 4189483 = 71221211 / (7 + 1 + 2 + 2 + 1 + 2 + 1 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71221211.

It is not an unprimeable number, because it can be changed into a prime (71221217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2094725 + ... + 2094758.

It is an arithmetic number, because the mean of its divisors is an integer number (18852678).

Almost surely, 2^71221211 is an apocalyptic number.

71221211 is a deficient number, since it is larger than the sum of its proper divisors (4189501).

71221211 is a wasteful number, since it uses less digits than its factorization.

71221211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4189500.

The product of its digits is 56, while the sum is 17.

The square root of 71221211 is about 8439.2660225875. The cubic root of 71221211 is about 414.5113734273.

Adding to 71221211 its reverse (11212217), we get a palindrome (82433428).

The spelling of 71221211 in words is "seventy-one million, two hundred twenty-one thousand, two hundred eleven".