20001012100021 has 2 divisors, whose sum is σ = 20001012100022. Its totient is φ = 20001012100020.

The previous prime is 20001012099953. The next prime is 20001012100031. The reversal of 20001012100021 is 12000121010002.

It is an a-pointer prime, because the next prime (20001012100031) can be obtained adding 20001012100021 to its sum of digits (10).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14811614199396 + 5189397900625 = 3848586^2 + 2278025^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001012100021 - 2¹⁹ = 20001011575733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001012099980 and 20001012100007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001012100031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000506050010 + 10000506050011.

It is an arithmetic number, because the mean of its divisors is an integer number (10000506050011).

Almost surely, 2^{20001012100021} is an apocalyptic number.

It is an amenable number.

20001012100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001012100021 is an equidigital number, since it uses as much as digits as its factorization.

20001012100021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20001012100021 its reverse (12000121010002), we get a palindrome (32001133110023).

The spelling of 20001012100021 in words is "twenty trillion, one billion, twelve million, one hundred thousand, twenty-one".