825621217 has 2 divisors, whose sum is σ = 825621218. Its totient is φ = 825621216.

The previous prime is 825621197. The next prime is 825621241. The reversal of 825621217 is 712126528.

It is a happy number.

825621217 is nontrivially palindromic in base 11.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 810597841 + 15023376 = 28471^2 + 3876^2 .

It is a cyclic number.

It is not a de Polignac number, because 825621217 - 2⁷ = 825621089 is a prime.

It is a super-2 number, since 2×825621217² = 1363300787921122178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (825627217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412810608 + 412810609.

It is an arithmetic number, because the mean of its divisors is an integer number (412810609).

Almost surely, 2^825621217 is an apocalyptic number.

It is an amenable number.

825621217 is a deficient number, since it is larger than the sum of its proper divisors (1).

825621217 is an equidigital number, since it uses as much as digits as its factorization.

825621217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 34.

The square root of 825621217 is about 28733.6251976669. The cubic root of 825621217 is about 938.1240756608.

The spelling of 825621217 in words is "eight hundred twenty-five million, six hundred twenty-one thousand, two hundred seventeen".