2021816121 has 24 divisors (see below), whose sum is σ = 2922120576. Its totient is φ = 1242895680.

The previous prime is 2021816119. The next prime is 2021816129. The reversal of 2021816121 is 1216181202.

2021816121 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2021816121 - 2¹ = 2021816119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2021816091 and 2021816100.

It is not an unprimeable number, because it can be changed into a prime (2021816129) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 755616 + ... + 758286.

It is an arithmetic number, because the mean of its divisors is an integer number (121755024).

Almost surely, 2^2021816121 is an apocalyptic number.

It is an amenable number.

2021816121 is a deficient number, since it is larger than the sum of its proper divisors (900304455).

2021816121 is a wasteful number, since it uses less digits than its factorization.

2021816121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4193 (or 4180 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 2021816121 is about 44964.6096502572. The cubic root of 2021816121 is about 1264.4855914883.

Adding to 2021816121 its reverse (1216181202), we get a palindrome (3237997323).

The spelling of 2021816121 in words is "two billion, twenty-one million, eight hundred sixteen thousand, one hundred twenty-one".