643517 has 12 divisors (see below), whose sum is σ = 782496. Its totient is φ = 526680.

The previous prime is 643507. The next prime is 643523. The reversal of 643517 is 715346.

It is not a de Polignac number, because 643517 - 2⁶ = 643453 is a prime.

It is a super-2 number, since 2×643517² = 828228258578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643507) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 842 + ... + 1412.

It is an arithmetic number, because the mean of its divisors is an integer number (65208).

2⁶⁴³⁵¹⁷ is an apocalyptic number.

It is an amenable number.

643517 is a deficient number, since it is larger than the sum of its proper divisors (138979).

643517 is a wasteful number, since it uses less digits than its factorization.

643517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608 (or 601 counting only the distinct ones).

The product of its digits is 2520, while the sum is 26.

The square root of 643517 is about 802.1951134232. The cubic root of 643517 is about 86.3349565477.

The spelling of 643517 in words is "six hundred forty-three thousand, five hundred seventeen".