20724144 has 80 divisors (see below), whose sum is σ = 62876928. Its totient is φ = 5757696.

The previous prime is 20724097. The next prime is 20724161. The reversal of 20724144 is 44142702.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11599 + ... + 13265.

Almost surely, 2^20724144 is an apocalyptic number.

20724144 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 20724144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31438464).

20724144 is an abundant number, since it is smaller than the sum of its proper divisors (42152784).

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

20724144 is a wasteful number, since it uses less digits than its factorization.

20724144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1722 (or 1716 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 24.

The square root of 20724144 is about 4552.3778402061. The cubic root of 20724144 is about 274.6790481531.

Adding to 20724144 its reverse (44142702), we get a palindrome (64866846).

It can be divided in two parts, 2072 and 4144, that added together give a triangular number (6216 = T₁₁₁).

The spelling of 20724144 in words is "twenty million, seven hundred twenty-four thousand, one hundred forty-four".