21012120201001 has 2 divisors, whose sum is σ = 21012120201002. Its totient is φ = 21012120201000.

The previous prime is 21012120200989. The next prime is 21012120201011. The reversal of 21012120201001 is 10010202121012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12478132353600 + 8533987847401 = 3532440^2 + 2921299^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012120201001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012120201011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506060100500 + 10506060100501.

It is an arithmetic number, because the mean of its divisors is an integer number (10506060100501).

Almost surely, 2^{21012120201001} is an apocalyptic number.

It is an amenable number.

21012120201001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012120201001 is an equidigital number, since it uses as much as digits as its factorization.

21012120201001 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 21012120201001 its reverse (10010202121012), we get a palindrome (31022322322013).

The spelling of 21012120201001 in words is "twenty-one trillion, twelve billion, one hundred twenty million, two hundred one thousand, one".