20385665 has 8 divisors (see below), whose sum is σ = 24619560. Its totient is φ = 16204032.

The previous prime is 20385653. The next prime is 20385671. The reversal of 20385665 is 56658302.

It can be written as a sum of positive squares in 4 ways, for example, as 18496 + 20367169 = 136^2 + 4513^2 .

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 20385665 - 2⁴ = 20385649 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12200 + ... + 13769.

It is an arithmetic number, because the mean of its divisors is an integer number (3077445).

Almost surely, 2^20385665 is an apocalyptic number.

It is an amenable number.

20385665 is a deficient number, since it is larger than the sum of its proper divisors (4233895).

20385665 is a wasteful number, since it uses less digits than its factorization.

20385665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26131.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 20385665 is about 4515.0487262044. The cubic root of 20385665 is about 273.1754251844.

The spelling of 20385665 in words is "twenty million, three hundred eighty-five thousand, six hundred sixty-five".