131221212321 has 8 divisors (see below), whose sum is σ = 174973487040. Its totient is φ = 87474872912.

The previous prime is 131221212307. The next prime is 131221212341. The reversal of 131221212321 is 123212122131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 131221212321 - 2¹⁵ = 131221179553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131221212341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1431981 + ... + 1520858.

It is an arithmetic number, because the mean of its divisors is an integer number (21871685880).

Almost surely, 2^131221212321 is an apocalyptic number.

It is an amenable number.

131221212321 is a deficient number, since it is larger than the sum of its proper divisors (43752274719).

131221212321 is a wasteful number, since it uses less digits than its factorization.

131221212321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2967655.

The product of its digits is 288, while the sum is 21.

Adding to 131221212321 its reverse (123212122131), we get a palindrome (254433334452).

The spelling of 131221212321 in words is "one hundred thirty-one billion, two hundred twenty-one million, two hundred twelve thousand, three hundred twenty-one".