2021111021 has 4 divisors (see below), whose sum is σ = 2055367200. Its totient is φ = 1986854844.

The previous prime is 2021110981. The next prime is 2021111041. The reversal of 2021111021 is 1201111202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1201111202 = 2 ⋅600555601.

It is a cyclic number.

It is not a de Polignac number, because 2021111021 - 2¹⁰ = 2021109997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021110993 and 2021111011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021111041) 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, 17128001 + ... + 17128118.

It is an arithmetic number, because the mean of its divisors is an integer number (513841800).

Almost surely, 2^2021111021 is an apocalyptic number.

It is an amenable number.

2021111021 is a deficient number, since it is larger than the sum of its proper divisors (34256179).

2021111021 is an equidigital number, since it uses as much as digits as its factorization.

2021111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34256178.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2021111021 is about 44956.7683558327. The cubic root of 2021111021 is about 1264.3385796924.

Adding to 2021111021 its reverse (1201111202), we get a palindrome (3222222223).

The spelling of 2021111021 in words is "two billion, twenty-one million, one hundred eleven thousand, twenty-one".