20012121021 has 8 divisors (see below), whose sum is σ = 27543564544. Its totient is φ = 12911045760.

The previous prime is 20012121007. The next prime is 20012121043. The reversal of 20012121021 is 12012121002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20012121021 - 2⁶ = 20012120957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20012120988 and 20012121006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012121001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107591956 + ... + 107592141.

It is an arithmetic number, because the mean of its divisors is an integer number (3442945568).

Almost surely, 2^20012121021 is an apocalyptic number.

It is an amenable number.

20012121021 is a deficient number, since it is larger than the sum of its proper divisors (7531443523).

20012121021 is a wasteful number, since it uses less digits than its factorization.

20012121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215184131.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20012121021 its reverse (12012121002), we get a palindrome (32024242023).

The spelling of 20012121021 in words is "twenty billion, twelve million, one hundred twenty-one thousand, twenty-one".