1221231220133 has 4 divisors (see below), whose sum is σ = 1274328229728. Its totient is φ = 1168134210540.

The previous prime is 1221231220127. The next prime is 1221231220147. The reversal of 1221231220133 is 3310221321221.

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 1221231220133 - 2¹⁴ = 1221231203749 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 53097009571 = 1221231220133 / (1 + 2 + 2 + 1 + 2 + 3 + 1 + 2 + 2 + 0 + 1 + 3 + 3).

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221231220099 and 1221231220108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221231220933) 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, 26548504763 + ... + 26548504808.

It is an arithmetic number, because the mean of its divisors is an integer number (318582057432).

Almost surely, 2^{1221231220133} is an apocalyptic number.

It is an amenable number.

1221231220133 is a deficient number, since it is larger than the sum of its proper divisors (53097009595).

1221231220133 is an equidigital number, since it uses as much as digits as its factorization.

1221231220133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53097009594.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 1221231220133 its reverse (3310221321221), we get a palindrome (4531452541354).

The spelling of 1221231220133 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-one million, two hundred twenty thousand, one hundred thirty-three".