2021212121 has 8 divisors (see below), whose sum is σ = 2086937088. Its totient is φ = 1955520000.

The previous prime is 2021212117. The next prime is 2021212133. The reversal of 2021212121 is 1212121202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2021212121 - 2² = 2021212117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021212096 and 2021212105.

It is not an unprimeable number, because it can be changed into a prime (2021212321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205721 + ... + 215321.

It is an arithmetic number, because the mean of its divisors is an integer number (260867136).

Almost surely, 2^2021212121 is an apocalyptic number.

It is an amenable number.

2021212121 is a deficient number, since it is larger than the sum of its proper divisors (65724967).

2021212121 is an equidigital number, since it uses as much as digits as its factorization.

2021212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16423.

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

The square root of 2021212121 is about 44957.8927553327. The cubic root of 2021212121 is about 1264.3596609191.

Adding to 2021212121 its reverse (1212121202), we get a palindrome (3233333323).

It can be divided in two parts, 202 and 1212121, that multiplied together give a palindrome (244848442).

The spelling of 2021212121 in words is "two billion, twenty-one million, two hundred twelve thousand, one hundred twenty-one".