20040645 has 16 divisors (see below), whose sum is σ = 32185152. Its totient is φ = 10648320.

The previous prime is 20040619. The next prime is 20040667. The reversal of 20040645 is 54604002.

It is a happy number.

It is not a de Polignac number, because 20040645 - 2⁹ = 20040133 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 1885 + ... + 6605.

It is an arithmetic number, because the mean of its divisors is an integer number (2011572).

Almost surely, 2^20040645 is an apocalyptic number.

It is an amenable number.

20040645 is a deficient number, since it is larger than the sum of its proper divisors (12144507).

20040645 is a wasteful number, since it uses less digits than its factorization.

20040645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5012.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20040645 is about 4476.6778977273. The cubic root of 20040645 is about 271.6255164105.

Adding to 20040645 its reverse (54604002), we get a palindrome (74644647).

The spelling of 20040645 in words is "twenty million, forty thousand, six hundred forty-five".