643525 has 6 divisors (see below), whose sum is σ = 798002. Its totient is φ = 514800.

The previous prime is 643523. The next prime is 643547. The reversal of 643525 is 525346.

643525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 79524 + 564001 = 282^2 + 751^2 .

It is not a de Polignac number, because 643525 - 2¹ = 643523 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 25741 = 643525 / (6 + 4 + 3 + 5 + 2 + 5).

It is a d-powerful number, because it can be written as 6⁷ + 4⁹ + 5⁵ + 3⁹ + 2⁹ + 5⁷ .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643523) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12846 + ... + 12895.

2⁶⁴³⁵²⁵ is an apocalyptic number.

It is an amenable number.

643525 is a deficient number, since it is larger than the sum of its proper divisors (154477).

643525 is a wasteful number, since it uses less digits than its factorization.

643525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25751 (or 25746 counting only the distinct ones).

The product of its digits is 3600, while the sum is 25.

The square root of 643525 is about 802.2000997257. The cubic root of 643525 is about 86.3353143092.

The spelling of 643525 in words is "six hundred forty-three thousand, five hundred twenty-five".