231321203221 has 2 divisors, whose sum is σ = 231321203222. Its totient is φ = 231321203220.

The previous prime is 231321203213. The next prime is 231321203231. The reversal of 231321203221 is 122302123132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 225003179025 + 6318024196 = 474345^2 + 79486^2 .

It is a cyclic number.

It is not a de Polignac number, because 231321203221 - 2³ = 231321203213 is a prime.

It is a super-2 number, since 2×231321203221² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 231321203192 and 231321203201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231321203231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115660601610 + 115660601611.

It is an arithmetic number, because the mean of its divisors is an integer number (115660601611).

Almost surely, 2^231321203221 is an apocalyptic number.

It is an amenable number.

231321203221 is a deficient number, since it is larger than the sum of its proper divisors (1).

231321203221 is an equidigital number, since it uses as much as digits as its factorization.

231321203221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 231321203221 its reverse (122302123132), we get a palindrome (353623326353).

The spelling of 231321203221 in words is "two hundred thirty-one billion, three hundred twenty-one million, two hundred three thousand, two hundred twenty-one".