643526 has 16 divisors (see below), whose sum is σ = 1061424. Its totient is φ = 290784.

The previous prime is 643523. The next prime is 643547. The reversal of 643526 is 625346.

643526 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 643495 and 643504.

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 7 ways as a sum of consecutive naturals, for example, 1145 + ... + 1611.

It is an arithmetic number, because the mean of its divisors is an integer number (66339).

2⁶⁴³⁵²⁶ is an apocalyptic number.

643526 is a deficient number, since it is larger than the sum of its proper divisors (417898).

643526 is a wasteful number, since it uses less digits than its factorization.

643526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535.

The product of its digits is 4320, while the sum is 26.

The square root of 643526 is about 802.2007230114. The cubic root of 643526 is about 86.3353590291.

The spelling of 643526 in words is "six hundred forty-three thousand, five hundred twenty-six".