2121404081 has 2 divisors, whose sum is σ = 2121404082. Its totient is φ = 2121404080.

The previous prime is 2121404071. The next prime is 2121404111. The reversal of 2121404081 is 1804041212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2121063025 + 341056 = 46055^2 + 584^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121404081 - 2¹⁸ = 2121141937 is a prime.

It is a super-2 number, since 2×2121404081² = 9000710549766909122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2121404071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060702040 + 1060702041.

It is an arithmetic number, because the mean of its divisors is an integer number (1060702041).

Almost surely, 2^2121404081 is an apocalyptic number.

It is an amenable number.

2121404081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121404081 is an equidigital number, since it uses as much as digits as its factorization.

2121404081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 2121404081 is about 46058.7025544576. The cubic root of 2121404081 is about 1284.9151999837.

Adding to 2121404081 its reverse (1804041212), we get a palindrome (3925445293).

The spelling of 2121404081 in words is "two billion, one hundred twenty-one million, four hundred four thousand, eighty-one".