1311240455221 has 4 divisors (see below), whose sum is σ = 1330811208352. Its totient is φ = 1291669702092.

The previous prime is 1311240455141. The next prime is 1311240455243. The reversal of 1311240455221 is 1225540421131.

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 1311240455221 - 2⁷ = 1311240455093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311240453221) 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, 9785376465 + ... + 9785376598.

It is an arithmetic number, because the mean of its divisors is an integer number (332702802088).

Almost surely, 2^{1311240455221} is an apocalyptic number.

It is an amenable number.

1311240455221 is a deficient number, since it is larger than the sum of its proper divisors (19570753131).

1311240455221 is an equidigital number, since it uses as much as digits as its factorization.

1311240455221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19570753130.

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 1311240455221 its reverse (1225540421131), we get a palindrome (2536780876352).

The spelling of 1311240455221 in words is "one trillion, three hundred eleven billion, two hundred forty million, four hundred fifty-five thousand, two hundred twenty-one".