131571721221 has 8 divisors (see below), whose sum is σ = 185748312384. Its totient is φ = 82554805440.

The previous prime is 131571721219. The next prime is 131571721231. The reversal of 131571721221 is 122127175131.

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

It is not a de Polignac number, because 131571721221 - 2¹ = 131571721219 is a prime.

It is a super-2 number, since 2×131571721221² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131571721231) 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, 1289918785 + ... + 1289918886.

It is an arithmetic number, because the mean of its divisors is an integer number (23218539048).

Almost surely, 2^131571721221 is an apocalyptic number.

It is an amenable number.

131571721221 is a deficient number, since it is larger than the sum of its proper divisors (54176591163).

131571721221 is a wasteful number, since it uses less digits than its factorization.

131571721221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2579837691.

The product of its digits is 5880, while the sum is 33.

Adding to 131571721221 its reverse (122127175131), we get a palindrome (253698896352).

The spelling of 131571721221 in words is "one hundred thirty-one billion, five hundred seventy-one million, seven hundred twenty-one thousand, two hundred twenty-one".