20138309 has 8 divisors (see below), whose sum is σ = 21240480. Its totient is φ = 19040400.

The previous prime is 20138303. The next prime is 20138311. The reversal of 20138309 is 90383102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20138309 - 2²⁴ = 3361093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20138303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14954 + ... + 16244.

It is an arithmetic number, because the mean of its divisors is an integer number (2655060).

Almost surely, 2^20138309 is an apocalyptic number.

It is an amenable number.

20138309 is a deficient number, since it is larger than the sum of its proper divisors (1102171).

20138309 is a wasteful number, since it uses less digits than its factorization.

20138309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2131.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20138309 is about 4487.5727292157. The cubic root of 20138309 is about 272.0660387878.

The spelling of 20138309 in words is "twenty million, one hundred thirty-eight thousand, three hundred nine".