20121000122021 has 4 divisors (see below), whose sum is σ = 20121355303200. Its totient is φ = 20120644940844.

The previous prime is 20121000122009. The next prime is 20121000122059. The reversal of 20121000122021 is 12022100012102.

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 a de Polignac number, because none of the positive numbers 2^k-20121000122021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121000121987 and 20121000122005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121002122021) 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, 177505601 + ... + 177618918.

It is an arithmetic number, because the mean of its divisors is an integer number (5030338825800).

Almost surely, 2^{20121000122021} is an apocalyptic number.

It is an amenable number.

20121000122021 is a deficient number, since it is larger than the sum of its proper divisors (355181179).

20121000122021 is an equidigital number, since it uses as much as digits as its factorization.

20121000122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355181178.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121000122021 its reverse (12022100012102), we get a palindrome (32143100134123).

The spelling of 20121000122021 in words is "twenty trillion, one hundred twenty-one billion, one hundred twenty-two thousand, twenty-one".