2121422521 has 4 divisors (see below), whose sum is σ = 2121635044. Its totient is φ = 2121210000.

The previous prime is 2121422519. The next prime is 2121422531. The reversal of 2121422521 is 1252241212.

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 822829225 + 1298593296 = 28685^2 + 36036^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121422521 - 2¹ = 2121422519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121422492 and 2121422501.

It is not an unprimeable number, because it can be changed into a prime (2121422531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90510 + ... + 111511.

It is an arithmetic number, because the mean of its divisors is an integer number (530408761).

Almost surely, 2^2121422521 is an apocalyptic number.

It is an amenable number.

2121422521 is a deficient number, since it is larger than the sum of its proper divisors (212523).

2121422521 is a wasteful number, since it uses less digits than its factorization.

2121422521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212522.

The product of its digits is 640, while the sum is 22.

The square root of 2121422521 is about 46058.9027333479. The cubic root of 2121422521 is about 1284.9189229531.

Adding to 2121422521 its reverse (1252241212), we get a palindrome (3373663733).

The spelling of 2121422521 in words is "two billion, one hundred twenty-one million, four hundred twenty-two thousand, five hundred twenty-one".