39820009 has 4 divisors (see below), whose sum is σ = 40110804. Its totient is φ = 39529216.

The previous prime is 39819977. The next prime is 39820037. The reversal of 39820009 is 90002893.

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 29192409 + 10627600 = 5403^2 + 3260^2 .

It is a cyclic number.

It is not a de Polignac number, because 39820009 - 2⁵ = 39819977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39826009) 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, 145192 + ... + 145465.

It is an arithmetic number, because the mean of its divisors is an integer number (10027701).

Almost surely, 2^39820009 is an apocalyptic number.

It is an amenable number.

39820009 is a deficient number, since it is larger than the sum of its proper divisors (290795).

39820009 is a wasteful number, since it uses less digits than its factorization.

39820009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290794.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 39820009 is about 6310.3097388322. The cubic root of 39820009 is about 341.4814508595.

The spelling of 39820009 in words is "thirty-nine million, eight hundred twenty thousand, nine".