2123242021 has 4 divisors (see below), whose sum is σ = 2145131212. Its totient is φ = 2101352832.

The previous prime is 2123241997. The next prime is 2123242133. The reversal of 2123242021 is 1202423212.

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 1192320900 + 930921121 = 34530^2 + 30511^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123242021 - 2¹³ = 2123233829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2123242021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123242621) 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, 10944450 + ... + 10944643.

It is an arithmetic number, because the mean of its divisors is an integer number (536282803).

Almost surely, 2^2123242021 is an apocalyptic number.

It is an amenable number.

2123242021 is a deficient number, since it is larger than the sum of its proper divisors (21889191).

2123242021 is an equidigital number, since it uses as much as digits as its factorization.

2123242021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21889190.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 2123242021 is about 46078.6503817115. The cubic root of 2123242021 is about 1285.2861673977.

Adding to 2123242021 its reverse (1202423212), we get a palindrome (3325665233).

The spelling of 2123242021 in words is "two billion, one hundred twenty-three million, two hundred forty-two thousand, twenty-one".