21012000010121 has 4 divisors (see below), whose sum is σ = 21299835626772. Its totient is φ = 20724164393472.

The previous prime is 21012000010103. The next prime is 21012000010129. The reversal of 21012000010121 is 12101000021012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14355914766400 + 6656085243721 = 3788920^2 + 2579939^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012000010121 - 2¹⁰ = 21012000009097 is a prime.

It is a super-3 number, since 3×21012000010121³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012000010129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143917808216 + ... + 143917808361.

It is an arithmetic number, because the mean of its divisors is an integer number (5324958906693).

Almost surely, 2^{21012000010121} is an apocalyptic number.

It is an amenable number.

21012000010121 is a deficient number, since it is larger than the sum of its proper divisors (287835616651).

21012000010121 is an equidigital number, since it uses as much as digits as its factorization.

21012000010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287835616650.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012000010121 its reverse (12101000021012), we get a palindrome (33113000031133).

The spelling of 21012000010121 in words is "twenty-one trillion, twelve billion, ten thousand, one hundred twenty-one".