1311213431021 has 8 divisors (see below), whose sum is σ = 1438718946840. Its totient is φ = 1187514050112.

The previous prime is 1311213430979. The next prime is 1311213431051. The reversal of 1311213431021 is 1201343121131.

It can be written as a sum of positive squares in 4 ways, for example, as 354514258921 + 956699172100 = 595411^2 + 978110^2 .

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

It is not a de Polignac number, because 1311213431021 - 2³⁴ = 1294033561837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311213431051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 951533006 + ... + 951534383.

It is an arithmetic number, because the mean of its divisors is an integer number (179839868355).

Almost surely, 2^{1311213431021} is an apocalyptic number.

It is an amenable number.

1311213431021 is a deficient number, since it is larger than the sum of its proper divisors (127505515819).

1311213431021 is a wasteful number, since it uses less digits than its factorization.

1311213431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903067455.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 1311213431021 its reverse (1201343121131), we get a palindrome (2512556552152).

The spelling of 1311213431021 in words is "one trillion, three hundred eleven billion, two hundred thirteen million, four hundred thirty-one thousand, twenty-one".