1210101000021 has 24 divisors (see below), whose sum is σ = 1795225254680. Its totient is φ = 784903965696.

The previous prime is 1210101000007. The next prime is 1210101000029. The reversal of 1210101000021 is 1200001010121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 509958804996 + 700142195025 = 714114^2 + 836745^2 .

It is not a de Polignac number, because 1210101000021 - 2²⁷ = 1209966782293 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210100999967 and 1210101000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210101000029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16923681 + ... + 16995033.

Almost surely, 2^{1210101000021} is an apocalyptic number.

It is an amenable number.

1210101000021 is a deficient number, since it is larger than the sum of its proper divisors (585124254659).

1210101000021 is a wasteful number, since it uses less digits than its factorization.

1210101000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122325 (or 122322 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1210101000021 its reverse (1200001010121), we get a palindrome (2410102010142).

The spelling of 1210101000021 in words is "one trillion, two hundred ten billion, one hundred one million, twenty-one", and thus it is an aban number.