643535 has 16 divisors (see below), whose sum is σ = 837216. Its totient is φ = 473088.

The previous prime is 643523. The next prime is 643547. The reversal of 643535 is 535346.

It is an interprime number because it is at equal distance from previous prime (643523) and next prime (643547).

It is a cyclic number.

It is not a de Polignac number, because 643535 - 2¹² = 639439 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5639 + ... + 5751.

It is an arithmetic number, because the mean of its divisors is an integer number (52326).

2⁶⁴³⁵³⁵ is an apocalyptic number.

643535 is a deficient number, since it is larger than the sum of its proper divisors (193681).

643535 is a wasteful number, since it uses less digits than its factorization.

643535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202.

The product of its digits is 5400, while the sum is 26.

The square root of 643535 is about 802.2063325604. The cubic root of 643535 is about 86.3357615068.

The spelling of 643535 in words is "six hundred forty-three thousand, five hundred thirty-five".