121212220211021 has 4 divisors (see below), whose sum is σ = 121212597308700. Its totient is φ = 121211843113344.

The previous prime is 121212220211009. The next prime is 121212220211051. The reversal of 121212220211021 is 120112022212121.

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 94064587716100 + 27147632494921 = 9698690^2 + 5210339^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121212220211021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121212220210984 and 121212220211002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212220211051) 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, 188066276 + ... + 188709693.

It is an arithmetic number, because the mean of its divisors is an integer number (30303149327175).

Almost surely, 2^{121212220211021} is an apocalyptic number.

It is an amenable number.

121212220211021 is a deficient number, since it is larger than the sum of its proper divisors (377097679).

121212220211021 is an equidigital number, since it uses as much as digits as its factorization.

121212220211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377097678.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 121212220211021 its reverse (120112022212121), we get a palindrome (241324242423142).

The spelling of 121212220211021 in words is "one hundred twenty-one trillion, two hundred twelve billion, two hundred twenty million, two hundred eleven thousand, twenty-one".