20502144 has 144 divisors (see below), whose sum is σ = 65298870. Its totient is φ = 6137856.

The previous prime is 20502143. The next prime is 20502151. The reversal of 20502144 is 44120502.

20502144 is a `hidden beast` number, since 20 + 502 + 144 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 20142144 + 360000 = 4488^2 + 600^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20502143) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 554094 + ... + 554130.

Almost surely, 2^20502144 is an apocalyptic number.

20502144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20502144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32649435).

20502144 is an abundant number, since it is smaller than the sum of its proper divisors (44796726).

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

20502144 is a wasteful number, since it uses less digits than its factorization.

20502144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 55 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 20502144 is about 4527.9293280704. The cubic root of 20502144 is about 273.6947245623.

Adding to 20502144 its reverse (44120502), we get a palindrome (64622646).

The spelling of 20502144 in words is "twenty million, five hundred two thousand, one hundred forty-four".