1243241321081 has 4 divisors (see below), whose sum is σ = 1244896769664. Its totient is φ = 1241585872500.

The previous prime is 1243241321027. The next prime is 1243241321083. The reversal of 1243241321081 is 1801231423421.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 1243241321081 - 2²² = 1243237126777 is a prime.

It is a super-2 number, since 2×1243241321081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1243241321083) 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, 827723165 + ... + 827724666.

It is an arithmetic number, because the mean of its divisors is an integer number (311224192416).

Almost surely, 2^{1243241321081} is an apocalyptic number.

It is an amenable number.

1243241321081 is a deficient number, since it is larger than the sum of its proper divisors (1655448583).

1243241321081 is an equidigital number, since it uses as much as digits as its factorization.

1243241321081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1655448582.

The product of its (nonzero) digits is 9216, while the sum is 32.

The spelling of 1243241321081 in words is "one trillion, two hundred forty-three billion, two hundred forty-one million, three hundred twenty-one thousand, eighty-one".