4069 has 4 divisors (see below), whose sum is σ = 4396. Its totient is φ = 3744.

The previous prime is 4057. The next prime is 4073. The reversal of 4069 is 9604.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 225 + 3844 = 15^2 + 62^2 .

It is not a de Polignac number, because 4069 - 2⁹ = 3557 is a prime.

It is a super-2 number, since 2×4069² = 33113522, which contains 22 as substring.

It is a Duffinian number.

4069 is a lucky number.

It is a plaindrome in base 5.

It is a nialpdrome in base 4, base 9 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4019) 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, 144 + ... + 169.

It is an arithmetic number, because the mean of its divisors is an integer number (1099).

2⁴⁰⁶⁹ is an apocalyptic number.

It is an amenable number.

4069 is a deficient number, since it is larger than the sum of its proper divisors (327).

4069 is a wasteful number, since it uses less digits than its factorization.

4069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 4069 is about 63.7887137353. The cubic root of 4069 is about 15.9647662182.

The spelling of 4069 in words is "four thousand, sixty-nine".