20381365 has 8 divisors (see below), whose sum is σ = 24682680. Its totient is φ = 16155072.

The previous prime is 20381363. The next prime is 20381369. The reversal of 20381365 is 56318302.

It can be written as a sum of positive squares in 4 ways, for example, as 1874161 + 18507204 = 1369^2 + 4302^2 .

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 20381365 - 2¹ = 20381363 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381363) by changing a digit.

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, 18154 + ... + 19243.

It is an arithmetic number, because the mean of its divisors is an integer number (3085335).

Almost surely, 2^20381365 is an apocalyptic number.

It is an amenable number.

20381365 is a deficient number, since it is larger than the sum of its proper divisors (4301315).

20381365 is a wasteful number, since it uses less digits than its factorization.

20381365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37511.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20381365 is about 4514.5725157538. The cubic root of 20381365 is about 273.1562166387.

Adding to 20381365 its reverse (56318302), we get a palindrome (76699667).

It can be divided in two parts, 2038 and 1365, that added together give a triangular number (3403 = T₈₂).

The spelling of 20381365 in words is "twenty million, three hundred eighty-one thousand, three hundred sixty-five".