20504144 has 40 divisors (see below), whose sum is σ = 41687808. Its totient is φ = 9757440.

The previous prime is 20504137. The next prime is 20504147. The reversal of 20504144 is 44140502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20504147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32924 + ... + 33540.

Almost surely, 2^20504144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20504144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20843904).

20504144 is an abundant number, since it is smaller than the sum of its proper divisors (21183664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20504144 is a wasteful number, since it uses less digits than its factorization.

20504144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723 (or 717 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 20504144 is about 4528.1501741881. The cubic root of 20504144 is about 273.7036239836.

Adding to 20504144 its reverse (44140502), we get a palindrome (64644646).

The spelling of 20504144 in words is "twenty million, five hundred four thousand, one hundred forty-four".