20122220212121 has 4 divisors (see below), whose sum is σ = 20122243719732. Its totient is φ = 20122196704512.

The previous prime is 20122220212097. The next prime is 20122220212301. The reversal of 20122220212121 is 12121202222102.

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 11341665972121 + 8780554240000 = 3367739^2 + 2963200^2 .

It is a cyclic number.

It is not a de Polignac number, because 20122220212121 - 2²² = 20122216017817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20122220212093 and 20122220212102.

It is not an unprimeable number, because it can be changed into a prime (20122220215121) 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, 10419320 + ... + 12198633.

It is an arithmetic number, because the mean of its divisors is an integer number (5030560929933).

Almost surely, 2^{20122220212121} is an apocalyptic number.

It is an amenable number.

20122220212121 is a deficient number, since it is larger than the sum of its proper divisors (23507611).

20122220212121 is an equidigital number, since it uses as much as digits as its factorization.

20122220212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23507610.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 20122220212121 its reverse (12121202222102), we get a palindrome (32243422434223).

The spelling of 20122220212121 in words is "twenty trillion, one hundred twenty-two billion, two hundred twenty million, two hundred twelve thousand, one hundred twenty-one".