521643225 has 24 divisors (see below), whose sum is σ = 878729472. Its totient is φ = 272958400.

The previous prime is 521643223. The next prime is 521643247. The reversal of 521643225 is 522346125.

It is not a de Polignac number, because 521643225 - 2¹ = 521643223 is a prime.

It is a super-2 number, since 2×521643225² = 544223308376801250, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 521643192 and 521643201.

It is not an unprimeable number, because it can be changed into a prime (521643223) 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 in 23 ways as a sum of consecutive naturals, for example, 61641 + ... + 69590.

It is an arithmetic number, because the mean of its divisors is an integer number (36613728).

Almost surely, 2^521643225 is an apocalyptic number.

It is an amenable number.

521643225 is a deficient number, since it is larger than the sum of its proper divisors (357086247).

521643225 is a wasteful number, since it uses less digits than its factorization.

521643225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131297 (or 131292 counting only the distinct ones).

The product of its digits is 14400, while the sum is 30.

The square root of 521643225 is about 22839.5101742572. The cubic root of 521643225 is about 804.9913068259.

The spelling of 521643225 in words is "five hundred twenty-one million, six hundred forty-three thousand, two hundred twenty-five".