11531065642221 has 4 divisors (see below), whose sum is σ = 15374754189632. Its totient is φ = 7687377094812.

The previous prime is 11531065642211. The next prime is 11531065642279. The reversal of 11531065642221 is 12224656013511.

11531065642221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11531065642221 - 2¹⁴ = 11531065625837 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11531065642221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531065642211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1921844273701 + ... + 1921844273706.

It is an arithmetic number, because the mean of its divisors is an integer number (3843688547408).

Almost surely, 2^{11531065642221} is an apocalyptic number.

It is an amenable number.

11531065642221 is a deficient number, since it is larger than the sum of its proper divisors (3843688547411).

11531065642221 is an equidigital number, since it uses as much as digits as its factorization.

11531065642221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3843688547410.

The product of its (nonzero) digits is 86400, while the sum is 39.

The spelling of 11531065642221 in words is "eleven trillion, five hundred thirty-one billion, sixty-five million, six hundred forty-two thousand, two hundred twenty-one".