21000002010121 has 8 divisors (see below), whose sum is σ = 21724250059080. Its totient is φ = 20275761297792.

The previous prime is 21000002010077. The next prime is 21000002010131. The reversal of 21000002010121 is 12101020000012.

It can be written as a sum of positive squares in 4 ways, for example, as 12229288761600 + 8770713248521 = 3497040^2 + 2961539^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21000002010121 - 2³⁷ = 20862563056649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000002010098 and 21000002010107.

It is not an unprimeable number, because it can be changed into a prime (21000002010131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4341771 + ... + 7800703.

It is an arithmetic number, because the mean of its divisors is an integer number (2715531257385).

Almost surely, 2^{21000002010121} is an apocalyptic number.

It is an amenable number.

21000002010121 is a deficient number, since it is larger than the sum of its proper divisors (724248048959).

21000002010121 is a wasteful number, since it uses less digits than its factorization.

21000002010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3668315.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000002010121 its reverse (12101020000012), we get a palindrome (33101022010133).

The spelling of 21000002010121 in words is "twenty-one trillion, two million, ten thousand, one hundred twenty-one".