643169 has 4 divisors (see below), whose sum is σ = 677040. Its totient is φ = 609300.

The previous prime is 643129. The next prime is 643183. The reversal of 643169 is 961346.

643169 = T₄₄ + T₄₅ + ... + T₁₅₇.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643169 is a prime.

It is a super-2 number, since 2×643169² = 827332725122, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643169.

It is not an unprimeable number, because it can be changed into a prime (643129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16907 + ... + 16944.

It is an arithmetic number, because the mean of its divisors is an integer number (169260).

2⁶⁴³¹⁶⁹ is an apocalyptic number.

It is an amenable number.

643169 is a deficient number, since it is larger than the sum of its proper divisors (33871).

643169 is a wasteful number, since it uses less digits than its factorization.

643169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33870.

The product of its digits is 3888, while the sum is 29.

The square root of 643169 is about 801.9781792543. The cubic root of 643169 is about 86.3193910525.

The spelling of 643169 in words is "six hundred forty-three thousand, one hundred sixty-nine".