20138617 has 4 divisors (see below), whose sum is σ = 20174580. Its totient is φ = 20102656.

The previous prime is 20138609. The next prime is 20138633. The reversal of 20138617 is 71683102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71683102 = 2 ⋅35841551.

It can be written as a sum of positive squares in 2 ways, for example, as 13461561 + 6677056 = 3669^2 + 2584^2 .

It is a cyclic number.

It is not a de Polignac number, because 20138617 - 2³ = 20138609 is a prime.

It is a super-3 number, since 3×20138617³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20132617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17128 + ... + 18265.

It is an arithmetic number, because the mean of its divisors is an integer number (5043645).

Almost surely, 2^20138617 is an apocalyptic number.

It is an amenable number.

20138617 is a deficient number, since it is larger than the sum of its proper divisors (35963).

20138617 is an equidigital number, since it uses as much as digits as its factorization.

20138617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35962.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 20138617 is about 4487.6070460770. The cubic root of 20138617 is about 272.0674257946.

The spelling of 20138617 in words is "twenty million, one hundred thirty-eight thousand, six hundred seventeen".