21225329 has 2 divisors, whose sum is σ = 21225330. Its totient is φ = 21225328.

The previous prime is 21225317. The next prime is 21225349. The reversal of 21225329 is 92352212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17430625 + 3794704 = 4175^2 + 1948^2 .

It is a cyclic number.

It is not a de Polignac number, because 21225329 - 2²⁴ = 4448113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21225298 and 21225307.

It is not a weakly prime, because it can be changed into another prime (21225349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612664 + 10612665.

It is an arithmetic number, because the mean of its divisors is an integer number (10612665).

Almost surely, 2^21225329 is an apocalyptic number.

It is an amenable number.

21225329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225329 is an equidigital number, since it uses as much as digits as its factorization.

21225329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 26.

The square root of 21225329 is about 4607.0955058475. The cubic root of 21225329 is about 276.8756800273.

The spelling of 21225329 in words is "twenty-one million, two hundred twenty-five thousand, three hundred twenty-nine".