20520144 has 30 divisors (see below), whose sum is σ = 57428306. Its totient is φ = 6840000.

The previous prime is 20520103. The next prime is 20520161. The reversal of 20520144 is 44102502.

20520144 is a `hidden beast` number, since 2 + 0 + 520 + 144 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16160400 + 4359744 = 4020^2 + 2088^2 .

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 71107 + ... + 71394.

Almost surely, 2^20520144 is an apocalyptic number.

20520144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20520144 is an abundant number, since it is smaller than the sum of its proper divisors (36908162).

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

20520144 is a wasteful number, since it uses less digits than its factorization.

20520144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142515 (or 142506 counting only the distinct ones).

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

The square root of 20520144 is about 4529.9165555228. The cubic root of 20520144 is about 273.7747985291.

Adding to 20520144 its reverse (44102502), we get a palindrome (64622646).

The spelling of 20520144 in words is "twenty million, five hundred twenty thousand, one hundred forty-four".