21525089 has 2 divisors, whose sum is σ = 21525090. Its totient is φ = 21525088.

The previous prime is 21525071. The next prime is 21525109. The reversal of 21525089 is 98052512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14592400 + 6932689 = 3820^2 + 2633^2 .

It is a cyclic number.

It is not a de Polignac number, because 21525089 - 2¹⁶ = 21459553 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21525059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762544 + 10762545.

It is an arithmetic number, because the mean of its divisors is an integer number (10762545).

Almost surely, 2^21525089 is an apocalyptic number.

It is an amenable number.

21525089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21525089 is an equidigital number, since it uses as much as digits as its factorization.

21525089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 21525089 is about 4639.5138753969. The cubic root of 21525089 is about 278.1730070562.

The spelling of 21525089 in words is "twenty-one million, five hundred twenty-five thousand, eighty-nine".