20000121000021 has 8 divisors (see below), whose sum is σ = 29629808888960. Its totient is φ = 13333413999996.

The previous prime is 20000120999939. The next prime is 20000121000037. The reversal of 20000121000021 is 12000012100002.

It is not a de Polignac number, because 20000121000021 - 2⁷ = 20000120999893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20000120999967 and 20000121000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000121000091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 370372611085 + ... + 370372611138.

It is an arithmetic number, because the mean of its divisors is an integer number (3703726111120).

Almost surely, 2^{20000121000021} is an apocalyptic number.

It is an amenable number.

20000121000021 is a deficient number, since it is larger than the sum of its proper divisors (9629687888939).

20000121000021 is an equidigital number, since it uses as much as digits as its factorization.

20000121000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740745222232 (or 740745222226 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20000121000021 its reverse (12000012100002), we get a palindrome (32000133100023).

The spelling of 20000121000021 in words is "twenty trillion, one hundred twenty-one million, twenty-one", and thus it is an aban number.