20535144 has 64 divisors (see below), whose sum is σ = 60579840. Its totient is φ = 5676480.

The previous prime is 20535131. The next prime is 20535149. The reversal of 20535144 is 44153502.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (20535149) by changing a digit.

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, 3237 + ... + 7179.

It is an arithmetic number, because the mean of its divisors is an integer number (946560).

Almost surely, 2^20535144 is an apocalyptic number.

20535144 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 20535144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30289920).

20535144 is an abundant number, since it is smaller than the sum of its proper divisors (40044696).

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

20535144 is a wasteful number, since it uses less digits than its factorization.

20535144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3990 (or 3986 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20535144 is about 4531.5719127031. The cubic root of 20535144 is about 273.8414910720.

Adding to 20535144 its reverse (44153502), we get a palindrome (64688646).

The spelling of 20535144 in words is "twenty million, five hundred thirty-five thousand, one hundred forty-four".