21200121012001 has 2 divisors, whose sum is σ = 21200121012002. Its totient is φ = 21200121012000.

The previous prime is 21200121011959. The next prime is 21200121012047. The reversal of 21200121012001 is 10021012100212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12367010088976 + 8833110923025 = 3516676^2 + 2972055^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200121012001 - 2¹⁷ = 21200120880929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21200121019001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600060506000 + 10600060506001.

It is an arithmetic number, because the mean of its divisors is an integer number (10600060506001).

Almost surely, 2^{21200121012001} is an apocalyptic number.

It is an amenable number.

21200121012001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200121012001 is an equidigital number, since it uses as much as digits as its factorization.

21200121012001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21200121012001 its reverse (10021012100212), we get a palindrome (31221133112213).

The spelling of 21200121012001 in words is "twenty-one trillion, two hundred billion, one hundred twenty-one million, twelve thousand, one".