20688365 has 8 divisors (see below), whose sum is σ = 25497240. Its totient is φ = 16103232.

The previous prime is 20688341. The next prime is 20688433. The reversal of 20688365 is 56388602.

It can be written as a sum of positive squares in 4 ways, for example, as 9223369 + 11464996 = 3037^2 + 3386^2 .

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 20688365 - 2⁶ = 20688301 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55730 + ... + 56099.

It is an arithmetic number, because the mean of its divisors is an integer number (3187155).

Almost surely, 2^20688365 is an apocalyptic number.

It is an amenable number.

20688365 is a deficient number, since it is larger than the sum of its proper divisors (4808875).

20688365 is a wasteful number, since it uses less digits than its factorization.

20688365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111871.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 20688365 is about 4548.4464380709. The cubic root of 20688365 is about 274.5208847606.

The spelling of 20688365 in words is "twenty million, six hundred eighty-eight thousand, three hundred sixty-five".