131223123221 has 4 divisors (see below), whose sum is σ = 134423687244. Its totient is φ = 128022559200.

The previous prime is 131223123197. The next prime is 131223123281. The reversal of 131223123221 is 122321322131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11500203121 + 119722920100 = 107239^2 + 346010^2 .

It is a cyclic number.

It is not a de Polignac number, because 131223123221 - 2²⁶ = 131156014357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131223123281) 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, 1600281950 + ... + 1600282031.

It is an arithmetic number, because the mean of its divisors is an integer number (33605921811).

Almost surely, 2^131223123221 is an apocalyptic number.

It is an amenable number.

131223123221 is a deficient number, since it is larger than the sum of its proper divisors (3200564023).

131223123221 is an equidigital number, since it uses as much as digits as its factorization.

131223123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3200564022.

The product of its digits is 864, while the sum is 23.

Adding to 131223123221 its reverse (122321322131), we get a palindrome (253544445352).

The spelling of 131223123221 in words is "one hundred thirty-one billion, two hundred twenty-three million, one hundred twenty-three thousand, two hundred twenty-one".