521649 has 12 divisors (see below), whose sum is σ = 760500. Its totient is φ = 344544.

The previous prime is 521641. The next prime is 521657. The reversal of 521649 is 946125.

521649 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (521641) and next prime (521657).

It can be written as a sum of positive squares in 2 ways, for example, as 90000 + 431649 = 300^2 + 657^2 .

It is not a de Polignac number, because 521649 - 2³ = 521641 is a prime.

521649 is strictly pandigital in base 7.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (521641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1147 + ... + 1535.

It is an arithmetic number, because the mean of its divisors is an integer number (63375).

2⁵²¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

521649 is a deficient number, since it is larger than the sum of its proper divisors (238851).

521649 is a wasteful number, since it uses less digits than its factorization.

521649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544 (or 541 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 521649 is about 722.2527258516. The cubic root of 521649 is about 80.4994277443.

The spelling of 521649 in words is "five hundred twenty-one thousand, six hundred forty-nine".