20065645 has 8 divisors (see below), whose sum is σ = 24473880. Its totient is φ = 15789120.

The previous prime is 20065621. The next prime is 20065657. The reversal of 20065645 is 54656002.

It can be written as a sum of positive squares in 4 ways, for example, as 111556 + 19954089 = 334^2 + 4467^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20065645 - 2¹⁵ = 20032877 is a prime.

It is a super-3 number, since 3×20065645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 32590 + ... + 33199.

It is an arithmetic number, because the mean of its divisors is an integer number (3059235).

Almost surely, 2^20065645 is an apocalyptic number.

It is an amenable number.

20065645 is a deficient number, since it is larger than the sum of its proper divisors (4408235).

20065645 is an equidigital number, since it uses as much as digits as its factorization.

20065645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65855.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 20065645 is about 4479.4692765996. The cubic root of 20065645 is about 271.7384172373.

The spelling of 20065645 in words is "twenty million, sixty-five thousand, six hundred forty-five".