320131221 has 4 divisors (see below), whose sum is σ = 426841632. Its totient is φ = 213420812.

The previous prime is 320131219. The next prime is 320131277. The reversal of 320131221 is 122131023.

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 320131221 - 2¹ = 320131219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 320131221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320131211) 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, 53355201 + ... + 53355206.

It is an arithmetic number, because the mean of its divisors is an integer number (106710408).

Almost surely, 2^320131221 is an apocalyptic number.

It is an amenable number.

320131221 is a deficient number, since it is larger than the sum of its proper divisors (106710411).

320131221 is a wasteful number, since it uses less digits than its factorization.

320131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106710410.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 320131221 is about 17892.2111825230. The cubic root of 320131221 is about 684.0838595415.

Adding to 320131221 its reverse (122131023), we get a palindrome (442262244).

The spelling of 320131221 in words is "three hundred twenty million, one hundred thirty-one thousand, two hundred twenty-one".