1643525 has 18 divisors (see below), whose sum is σ = 2212470. Its totient is φ = 1210560.

The previous prime is 1643513. The next prime is 1643539. The reversal of 1643525 is 5253461.

It is a Cunningham number, because it is equal to 1282²+1.

It can be written as a sum of positive squares in 9 ways, for example, as 1256641 + 386884 = 1121^2 + 622^2 .

It is not a de Polignac number, because 1643525 - 2⁶ = 1643461 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1643494 and 1643503.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4031 + ... + 4419.

It is an arithmetic number, because the mean of its divisors is an integer number (122915).

2^1643525 is an apocalyptic number.

It is an amenable number.

1643525 is a deficient number, since it is larger than the sum of its proper divisors (568945).

1643525 is a wasteful number, since it uses less digits than its factorization.

1643525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425 (or 407 counting only the distinct ones).

The product of its digits is 3600, while the sum is 26.

The square root of 1643525 is about 1282.0003900155. Note that the first 3 decimals coincide. The cubic root of 1643525 is about 118.0118009839.

Adding to 1643525 its reverse (5253461), we get a palindrome (6896986).

The spelling of 1643525 in words is "one million, six hundred forty-three thousand, five hundred twenty-five".