1212121222001 has 4 divisors (see below), whose sum is σ = 1283422470372. Its totient is φ = 1140819973632.

The previous prime is 1212121221959. The next prime is 1212121222009. The reversal of 1212121222001 is 1002221212121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 860562352225 + 351558869776 = 927665^2 + 592924^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212121222001 - 2¹⁰ = 1212121220977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 71301248353 = 1212121222001 / (1 + 2 + 1 + 2 + 1 + 2 + 1 + 2 + 2 + 2 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212121222009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35650624160 + ... + 35650624193.

It is an arithmetic number, because the mean of its divisors is an integer number (320855617593).

Almost surely, 2^{1212121222001} is an apocalyptic number.

It is an amenable number.

1212121222001 is a deficient number, since it is larger than the sum of its proper divisors (71301248371).

1212121222001 is an equidigital number, since it uses as much as digits as its factorization.

1212121222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71301248370.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1212121222001 its reverse (1002221212121), we get a palindrome (2214342434122).

The spelling of 1212121222001 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one".