1211020102021 has 4 divisors (see below), whose sum is σ = 1211026486572. Its totient is φ = 1211013717472.

The previous prime is 1211020102009. The next prime is 1211020102031. The reversal of 1211020102021 is 1202010201121.

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 13855879521 + 1197164222500 = 117711^2 + 1094150^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211020102021 - 2¹⁵ = 1211020069253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211020101992 and 1211020102010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211020102001) 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, 2898760 + ... + 3290113.

It is an arithmetic number, because the mean of its divisors is an integer number (302756621643).

Almost surely, 2^{1211020102021} is an apocalyptic number.

It is an amenable number.

1211020102021 is a deficient number, since it is larger than the sum of its proper divisors (6384551).

1211020102021 is an equidigital number, since it uses as much as digits as its factorization.

1211020102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6384550.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1211020102021 its reverse (1202010201121), we get a palindrome (2413030303142).

The spelling of 1211020102021 in words is "one trillion, two hundred eleven billion, twenty million, one hundred two thousand, twenty-one".