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20754 = 2321153

20754 has 12 divisors (see below), whose sum is σ = 45006. Its totient is φ = 6912.

The previous prime is 20753. The next prime is 20759. The reversal of 20754 is 45702.

Subtracting from 20754 its sum of digits (18), we obtain a 4-th power (20736 = 124).

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15129 + 5625 = 123^2 + 75^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1153 = 20754 / (2 + 0 + 7 + 5 + 4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 559 + ... + 594.

220754 is an apocalyptic number.

20754 is an abundant number, since it is smaller than the sum of its proper divisors (24252).

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

20754 is a wasteful number, since it uses less digits than its factorization.

20754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161 (or 1158 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 20754 is about 144.0624864425. The cubic root of 20754 is about 27.4810889267.

The spelling of 20754 in words is "twenty thousand, seven hundred fifty-four".

Divisors: 1 2 3 6 9 18 1153 2306 3459 6918 10377 20754