20440609 has 16 divisors (see below), whose sum is σ = 24330240. Its totient is φ = 16808400.

The previous prime is 20440601. The next prime is 20440639. The reversal of 20440609 is 90604402.

It is not a de Polignac number, because 20440609 - 2³ = 20440601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20440601) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17184 + ... + 18334.

It is an arithmetic number, because the mean of its divisors is an integer number (1520640).

Almost surely, 2^20440609 is an apocalyptic number.

It is an amenable number.

20440609 is a deficient number, since it is larger than the sum of its proper divisors (3889631).

20440609 is a wasteful number, since it uses less digits than its factorization.

20440609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20440609 is about 4521.1291731159. The cubic root of 20440609 is about 273.4206283076.

The spelling of 20440609 in words is "twenty million, four hundred forty thousand, six hundred nine".