20559040 has 56 divisors (see below), whose sum is σ = 50182272. Its totient is φ = 8017920.

The previous prime is 20558981. The next prime is 20559041. The reversal of 20559040 is 4095502.

It is a junction number, because it is equal to n+sod(n) for n = 20558996 and 20559014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20559041) 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 7 ways as a sum of consecutive naturals, for example, 12337 + ... + 13903.

It is an arithmetic number, because the mean of its divisors is an integer number (896112).

Almost surely, 2^20559040 is an apocalyptic number.

20559040 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 20559040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25091136).

20559040 is an abundant number, since it is smaller than the sum of its proper divisors (29623232).

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

20559040 is a wasteful number, since it uses less digits than its factorization.

20559040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1625 (or 1615 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20559040 is about 4534.2077588042. The cubic root of 20559040 is about 273.9476696908.

The spelling of 20559040 in words is "twenty million, five hundred fifty-nine thousand, forty".