21327289 has 2 divisors, whose sum is σ = 21327290. Its totient is φ = 21327288.

The previous prime is 21327263. The next prime is 21327301. The reversal of 21327289 is 98272312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19053225 + 2274064 = 4365^2 + 1508^2 .

It is a cyclic number.

It is not a de Polignac number, because 21327289 - 2¹³ = 21319097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21327259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10663644 + 10663645.

It is an arithmetic number, because the mean of its divisors is an integer number (10663645).

Almost surely, 2^21327289 is an apocalyptic number.

It is an amenable number.

21327289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21327289 is an equidigital number, since it uses as much as digits as its factorization.

21327289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 34.

The square root of 21327289 is about 4618.1477888868. The cubic root of 21327289 is about 277.3183140995.

The spelling of 21327289 in words is "twenty-one million, three hundred twenty-seven thousand, two hundred eighty-nine".