20388717 has 6 divisors (see below), whose sum is σ = 29450382. Its totient is φ = 13592472.

The previous prime is 20388583. The next prime is 20388727. The reversal of 20388717 is 71788302.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 84681 = 4506^2 + 291^2 .

It is not a de Polignac number, because 20388717 - 2⁸ = 20388461 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20388727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1132698 + ... + 1132715.

It is an arithmetic number, because the mean of its divisors is an integer number (4908397).

Almost surely, 2^20388717 is an apocalyptic number.

It is an amenable number.

20388717 is a deficient number, since it is larger than the sum of its proper divisors (9061665).

20388717 is a wasteful number, since it uses less digits than its factorization.

20388717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265419 (or 2265416 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 20388717 is about 4515.3866944039. The cubic root of 20388717 is about 273.1890571458.

The spelling of 20388717 in words is "twenty million, three hundred eighty-eight thousand, seven hundred seventeen".