1213420553221 has 4 divisors (see below), whose sum is σ = 1252563151744. Its totient is φ = 1174277954700.

The previous prime is 1213420553197. The next prime is 1213420553243. The reversal of 1213420553221 is 1223550243121.

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 1213420553221 - 2⁹ = 1213420552709 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 39142598491 = 1213420553221 / (1 + 2 + 1 + 3 + 4 + 2 + 0 + 5 + 5 + 3 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213420353221) 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, 19571299215 + ... + 19571299276.

It is an arithmetic number, because the mean of its divisors is an integer number (313140787936).

Almost surely, 2^{1213420553221} is an apocalyptic number.

It is an amenable number.

1213420553221 is a deficient number, since it is larger than the sum of its proper divisors (39142598523).

1213420553221 is an equidigital number, since it uses as much as digits as its factorization.

1213420553221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39142598522.

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 1213420553221 its reverse (1223550243121), we get a palindrome (2436970796342).

The spelling of 1213420553221 in words is "one trillion, two hundred thirteen billion, four hundred twenty million, five hundred fifty-three thousand, two hundred twenty-one".