1212220021121 has 4 divisors (see below), whose sum is σ = 1238011936512. Its totient is φ = 1186428105732.

The previous prime is 1212220021097. The next prime is 1212220021141. The reversal of 1212220021121 is 1211200222121.

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 1212220021121 - 2¹⁸ = 1212219758977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212220021121.

It is not an unprimeable number, because it can be changed into a prime (1212220021141) 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, 12895957625 + ... + 12895957718.

It is an arithmetic number, because the mean of its divisors is an integer number (309502984128).

Almost surely, 2^{1212220021121} is an apocalyptic number.

It is an amenable number.

1212220021121 is a deficient number, since it is larger than the sum of its proper divisors (25791915391).

1212220021121 is an equidigital number, since it uses as much as digits as its factorization.

1212220021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25791915390.

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

Adding to 1212220021121 its reverse (1211200222121), we get a palindrome (2423420243242).

The spelling of 1212220021121 in words is "one trillion, two hundred twelve billion, two hundred twenty million, twenty-one thousand, one hundred twenty-one".