21795289 has 2 divisors, whose sum is σ = 21795290. Its totient is φ = 21795288.

The previous prime is 21795259. The next prime is 21795307. The reversal of 21795289 is 98259712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21780889 + 14400 = 4667^2 + 120^2 .

It is a cyclic number.

It is not a de Polignac number, because 21795289 - 2⁷ = 21795161 is a prime.

It is not a weakly prime, because it can be changed into another prime (21795209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10897644 + 10897645.

It is an arithmetic number, because the mean of its divisors is an integer number (10897645).

Almost surely, 2^21795289 is an apocalyptic number.

It is an amenable number.

21795289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21795289 is an equidigital number, since it uses as much as digits as its factorization.

21795289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 21795289 is about 4668.5424920418. The cubic root of 21795289 is about 279.3321199163.

The spelling of 21795289 in words is "twenty-one million, seven hundred ninety-five thousand, two hundred eighty-nine".