21120089 has 2 divisors, whose sum is σ = 21120090. Its totient is φ = 21120088.

The previous prime is 21120079. The next prime is 21120109. The reversal of 21120089 is 98002112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16540489 + 4579600 = 4067^2 + 2140^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120089 - 2¹² = 21115993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21120019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560044 + 10560045.

It is an arithmetic number, because the mean of its divisors is an integer number (10560045).

Almost surely, 2^21120089 is an apocalyptic number.

It is an amenable number.

21120089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120089 is an equidigital number, since it uses as much as digits as its factorization.

21120089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 21120089 is about 4595.6598002898. The cubic root of 21120089 is about 276.4173174749.

The spelling of 21120089 in words is "twenty-one million, one hundred twenty thousand, eighty-nine".