21012121012001 has 64 divisors (see below), whose sum is σ = 26093637043200. Its totient is φ = 16513128529920.

The previous prime is 21012121011991. The next prime is 21012121012013. The reversal of 21012121012001 is 10021012121012.

It is not a de Polignac number, because 21012121012001 - 2³⁰ = 21011047270177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012121012801) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 236789321 + ... + 236878041.

It is an arithmetic number, because the mean of its divisors is an integer number (407713078800).

Almost surely, 2^{21012121012001} is an apocalyptic number.

It is an amenable number.

21012121012001 is a deficient number, since it is larger than the sum of its proper divisors (5081516031199).

21012121012001 is a wasteful number, since it uses less digits than its factorization.

21012121012001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89154.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21012121012001 its reverse (10021012121012), we get a palindrome (31033133133013).

The spelling of 21012121012001 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, twelve thousand, one".