21100012120001 has 2 divisors, whose sum is σ = 21100012120002. Its totient is φ = 21100012120000.

The previous prime is 21100012119973. The next prime is 21100012120049. The reversal of 21100012120001 is 10002121000112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11947426815025 + 9152585304976 = 3456505^2 + 3025324^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100012120001 - 2¹⁸ = 21100011857857 is a prime.

It is a super-2 number, since 2×21100012120001² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21100012120301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550006060000 + 10550006060001.

It is an arithmetic number, because the mean of its divisors is an integer number (10550006060001).

Almost surely, 2^{21100012120001} is an apocalyptic number.

It is an amenable number.

21100012120001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100012120001 is an equidigital number, since it uses as much as digits as its factorization.

21100012120001 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 11.

Adding to 21100012120001 its reverse (10002121000112), we get a palindrome (31102133120113).

The spelling of 21100012120001 in words is "twenty-one trillion, one hundred billion, twelve million, one hundred twenty thousand, one".