231013011221 has 2 divisors, whose sum is σ = 231013011222. Its totient is φ = 231013011220.

The previous prime is 231013011191. The next prime is 231013011227. The reversal of 231013011221 is 122110310132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207584116996 + 23428894225 = 455614^2 + 153065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231013011221 is a prime.

It is a super-2 number, since 2×231013011221² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 231013011221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231013011227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115506505610 + 115506505611.

It is an arithmetic number, because the mean of its divisors is an integer number (115506505611).

Almost surely, 2^231013011221 is an apocalyptic number.

It is an amenable number.

231013011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

231013011221 is an equidigital number, since it uses as much as digits as its factorization.

231013011221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 231013011221 its reverse (122110310132), we get a palindrome (353123321353).

The spelling of 231013011221 in words is "two hundred thirty-one billion, thirteen million, eleven thousand, two hundred twenty-one".