20718144 has 42 divisors (see below), whose sum is σ = 59386470. Its totient is φ = 6905856.

The previous prime is 20718109. The next prime is 20718149. The reversal of 20718144 is 44181702.

It can be written as a sum of positive squares in only one way, i.e., 20358144 + 360000 = 4512^2 + 600^2 .

It is not an unprimeable number, because it can be changed into a prime (20718149) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17409 + ... + 18560.

Almost surely, 2^20718144 is an apocalyptic number.

20718144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20718144 is an abundant number, since it is smaller than the sum of its proper divisors (38668326).

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

20718144 is a wasteful number, since it uses less digits than its factorization.

20718144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35987 (or 35974 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 20718144 is about 4551.7187962351. The cubic root of 20718144 is about 274.6525374745.

Adding to 20718144 its reverse (44181702), we get a palindrome (64899846).

The spelling of 20718144 in words is "twenty million, seven hundred eighteen thousand, one hundred forty-four".