1020210020021 has 4 divisors (see below), whose sum is σ = 1020455680332. Its totient is φ = 1019964359712.

The previous prime is 1020210019973. The next prime is 1020210020051. The reversal of 1020210020021 is 1200200120201.

It is a happy number.

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 102647188996 + 917562831025 = 320386^2 + 957895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020210020021 - 2¹⁸ = 1020209757877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020210019984 and 1020210020011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020210020051) 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, 122823926 + ... + 122832231.

It is an arithmetic number, because the mean of its divisors is an integer number (255113920083).

Almost surely, 2^{1020210020021} is an apocalyptic number.

It is an amenable number.

1020210020021 is a deficient number, since it is larger than the sum of its proper divisors (245660311).

1020210020021 is an equidigital number, since it uses as much as digits as its factorization.

1020210020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245660310.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 1020210020021 its reverse (1200200120201), we get a palindrome (2220410140222).

The spelling of 1020210020021 in words is "one trillion, twenty billion, two hundred ten million, twenty thousand, twenty-one".