20040644 has 12 divisors (see below), whose sum is σ = 37769004. Its totient is φ = 9249504.

The previous prime is 20040619. The next prime is 20040667. The reversal of 20040644 is 44604002.

It can be written as a sum of positive squares in 2 ways, for example, as 4674244 + 15366400 = 2162^2 + 3920^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192647 + ... + 192750.

It is an arithmetic number, because the mean of its divisors is an integer number (3147417).

Almost surely, 2^20040644 is an apocalyptic number.

It is an amenable number.

20040644 is a deficient number, since it is larger than the sum of its proper divisors (17728360).

20040644 is a wasteful number, since it uses less digits than its factorization.

20040644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385414 (or 385412 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 20040644 is about 4476.6777860373. The cubic root of 20040644 is about 271.6255118926.

Adding to 20040644 its reverse (44604002), we get a palindrome (64644646).

The spelling of 20040644 in words is "twenty million, forty thousand, six hundred forty-four".