20755840 has 128 divisors (see below), whose sum is σ = 58605120. Its totient is φ = 6881280.

The previous prime is 20755837. The next prime is 20755841. The reversal of 20755840 is 4855702.

It is a tau number, because it is divible by the number of its divisors (128).

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20755841) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 183624 + ... + 183736.

Almost surely, 2^20755840 is an apocalyptic number.

20755840 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 20755840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29302560).

20755840 is an abundant number, since it is smaller than the sum of its proper divisors (37849280).

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

20755840 is a wasteful number, since it uses less digits than its factorization.

20755840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 31.

The square root of 20755840 is about 4555.8577677535. The cubic root of 20755840 is about 274.8190103855.

The spelling of 20755840 in words is "twenty million, seven hundred fifty-five thousand, eight hundred forty".