71031221 has 4 divisors (see below), whose sum is σ = 72235200. Its totient is φ = 69827244.

The previous prime is 71031211. The next prime is 71031223. The reversal of 71031221 is 12213017.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71031221 - 2²⁶ = 3922357 is a prime.

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 71031221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71031223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 601901 + ... + 602018.

It is an arithmetic number, because the mean of its divisors is an integer number (18058800).

Almost surely, 2^71031221 is an apocalyptic number.

It is an amenable number.

71031221 is a deficient number, since it is larger than the sum of its proper divisors (1203979).

71031221 is a wasteful number, since it uses less digits than its factorization.

71031221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203978.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 71031221 is about 8428.0021950638. The cubic root of 71031221 is about 414.1424611047.

Adding to 71031221 its reverse (12213017), we get a palindrome (83244238).

The spelling of 71031221 in words is "seventy-one million, thirty-one thousand, two hundred twenty-one".