1321020213121 has 4 divisors (see below), whose sum is σ = 1509737386432. Its totient is φ = 1132303039812.

The previous prime is 1321020213113. The next prime is 1321020213131. The reversal of 1321020213121 is 1213120201231.

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 1321020213121 - 2³ = 1321020213113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321020213131) 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 3 ways as a sum of consecutive naturals, for example, 94358586645 + ... + 94358586658.

It is an arithmetic number, because the mean of its divisors is an integer number (377434346608).

Almost surely, 2^{1321020213121} is an apocalyptic number.

It is an amenable number.

1321020213121 is a deficient number, since it is larger than the sum of its proper divisors (188717173311).

1321020213121 is an equidigital number, since it uses as much as digits as its factorization.

1321020213121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188717173310.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1321020213121 its reverse (1213120201231), we get a palindrome (2534140414352).

The spelling of 1321020213121 in words is "one trillion, three hundred twenty-one billion, twenty million, two hundred thirteen thousand, one hundred twenty-one".