20442665 has 4 divisors (see below), whose sum is σ = 24531204. Its totient is φ = 16354128.

The previous prime is 20442661. The next prime is 20442691. The reversal of 20442665 is 56624402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16297369 + 4145296 = 4037^2 + 2036^2 .

It is a cyclic number.

It is not a de Polignac number, because 20442665 - 2² = 20442661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20442661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2044262 + ... + 2044271.

It is an arithmetic number, because the mean of its divisors is an integer number (6132801).

Almost surely, 2^20442665 is an apocalyptic number.

It is an amenable number.

20442665 is a deficient number, since it is larger than the sum of its proper divisors (4088539).

20442665 is an equidigital number, since it uses as much as digits as its factorization.

20442665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4088538.

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 20442665 is about 4521.3565442243. The cubic root of 20442665 is about 273.4297952550.

The spelling of 20442665 in words is "twenty million, four hundred forty-two thousand, six hundred sixty-five".