1210221200021 has 4 divisors (see below), whose sum is σ = 1210341498444. Its totient is φ = 1210100901600.

The previous prime is 1210221200003. The next prime is 1210221200039. The reversal of 1210221200021 is 1200021220121.

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

It is an interprime number because it is at equal distance from previous prime (1210221200003) and next prime (1210221200039).

It can be written as a sum of positive squares in 2 ways, for example, as 403612443025 + 806608756996 = 635305^2 + 898114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210221200021 - 2³⁴ = 1193041330837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210221199969 and 1210221200005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210221203021) 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, 60134120 + ... + 60154241.

It is an arithmetic number, because the mean of its divisors is an integer number (302585374611).

Almost surely, 2^{1210221200021} is an apocalyptic number.

It is an amenable number.

1210221200021 is a deficient number, since it is larger than the sum of its proper divisors (120298423).

1210221200021 is a wasteful number, since it uses less digits than its factorization.

1210221200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120298422.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1210221200021 its reverse (1200021220121), we get a palindrome (2410242420142).

The spelling of 1210221200021 in words is "one trillion, two hundred ten billion, two hundred twenty-one million, two hundred thousand, twenty-one".