20012121222121 has 4 divisors (see below), whose sum is σ = 22870995682432. Its totient is φ = 17153246761812.

The previous prime is 20012121222091. The next prime is 20012121222131. The reversal of 20012121222121 is 12122212121002.

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 not a de Polignac number, because 20012121222121 - 2³¹ = 20009973738473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20012121222131) 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, 1429437230145 + ... + 1429437230158.

It is an arithmetic number, because the mean of its divisors is an integer number (5717748920608).

Almost surely, 2^{20012121222121} is an apocalyptic number.

It is an amenable number.

20012121222121 is a deficient number, since it is larger than the sum of its proper divisors (2858874460311).

20012121222121 is an equidigital number, since it uses as much as digits as its factorization.

20012121222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2858874460310.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 20012121222121 its reverse (12122212121002), we get a palindrome (32134333343123).

The spelling of 20012121222121 in words is "twenty trillion, twelve billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".