20355540 has 48 divisors (see below), whose sum is σ = 57576960. Its totient is φ = 5372800.

The previous prime is 20355523. The next prime is 20355541. The reversal of 20355540 is 4555302.

It is a self number, because there is not a number n which added to its sum of digits gives 20355540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20355541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4381 + ... + 7739.

It is an arithmetic number, because the mean of its divisors is an integer number (1199520).

Almost surely, 2^20355540 is an apocalyptic number.

20355540 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 20355540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28788480).

20355540 is an abundant number, since it is smaller than the sum of its proper divisors (37221420).

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

20355540 is a wasteful number, since it uses less digits than its factorization.

20355540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3472 (or 3470 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 24.

The square root of 20355540 is about 4511.7114269421. The cubic root of 20355540 is about 273.0407968120.

The spelling of 20355540 in words is "twenty million, three hundred fifty-five thousand, five hundred forty".