20759940 has 144 divisors (see below), whose sum is σ = 67420080. Its totient is φ = 5160960.

The previous prime is 20759909. The next prime is 20759957. The reversal of 20759940 is 4995702.

20759940 is a `hidden beast` number, since 20 + 7 + 599 + 40 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 2663424 + 18096516 = 1632^2 + 4254^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20759895 and 20759904.

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 47 ways as a sum of consecutive naturals, for example, 213972 + ... + 214068.

It is an arithmetic number, because the mean of its divisors is an integer number (468195).

Almost surely, 2^20759940 is an apocalyptic number.

20759940 is a gapful number since it is divisible by the number (20) 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 20759940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33710040).

20759940 is an abundant number, since it is smaller than the sum of its proper divisors (46660140).

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

20759940 is a wasteful number, since it uses less digits than its factorization.

20759940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20759940 is about 4556.3077156838. The cubic root of 20759940 is about 274.8371046304.

The spelling of 20759940 in words is "twenty million, seven hundred fifty-nine thousand, nine hundred forty".