40069 has 4 divisors (see below), whose sum is σ = 42444. Its totient is φ = 37696.

The previous prime is 40063. The next prime is 40087. The reversal of 40069 is 96004.

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 19044 + 21025 = 138^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 40069 - 2⁵ = 40037 is a prime.

It is a super-2 number, since 2×40069² = 3211049522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

40069 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1162 + ... + 1195.

It is an arithmetic number, because the mean of its divisors is an integer number (10611).

2⁴⁰⁰⁶⁹ is an apocalyptic number.

It is an amenable number.

40069 is a deficient number, since it is larger than the sum of its proper divisors (2375).

40069 is a wasteful number, since it uses less digits than its factorization.

40069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2374.

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

The square root of 40069 is about 200.1724256735. The cubic root of 40069 is about 34.2191723605.

The spelling of 40069 in words is "forty thousand, sixty-nine".