825921521 has 2 divisors, whose sum is σ = 825921522. Its totient is φ = 825921520.

The previous prime is 825921491. The next prime is 825921539. The reversal of 825921521 is 125129528.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 424360000 + 401561521 = 20600^2 + 20039^2 .

It is a cyclic number.

It is not a de Polignac number, because 825921521 - 2⁶ = 825921457 is a prime.

It is not a weakly prime, because it can be changed into another prime (825921821) 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, 412960760 + 412960761.

It is an arithmetic number, because the mean of its divisors is an integer number (412960761).

Almost surely, 2^825921521 is an apocalyptic number.

It is an amenable number.

825921521 is a deficient number, since it is larger than the sum of its proper divisors (1).

825921521 is an equidigital number, since it uses as much as digits as its factorization.

825921521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 35.

The square root of 825921521 is about 28738.8503771463. The cubic root of 825921521 is about 938.2378034642.

The spelling of 825921521 in words is "eight hundred twenty-five million, nine hundred twenty-one thousand, five hundred twenty-one".