1001221202021 has 4 divisors (see below), whose sum is σ = 1001248115532. Its totient is φ = 1001194288512.

The previous prime is 1001221202011. The next prime is 1001221202027. The reversal of 1001221202021 is 1202021221001.

1001221202021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 1000828171396 + 393030625 = 1000414^2 + 19825^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001221202021 - 2¹⁸ = 1001220939877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1001221201987 and 1001221202005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001221202027) 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, 13400876 + ... + 13475381.

It is an arithmetic number, because the mean of its divisors is an integer number (250312028883).

Almost surely, 2^{1001221202021} is an apocalyptic number.

It is an amenable number.

1001221202021 is a deficient number, since it is larger than the sum of its proper divisors (26913511).

1001221202021 is an equidigital number, since it uses as much as digits as its factorization.

1001221202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26913510.

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

Adding to 1001221202021 its reverse (1202021221001), we get a palindrome (2203242423022).

The spelling of 1001221202021 in words is "one trillion, one billion, two hundred twenty-one million, two hundred two thousand, twenty-one".