20535540 has 48 divisors (see below), whose sum is σ = 58484160. Its totient is φ = 5382400.

The previous prime is 20535533. The next prime is 20535551. The reversal of 20535540 is 4553502.

It is a self number, because there is not a number n which added to its sum of digits gives 20535540.

It is a congruent number.

It is an unprimeable number.

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, 640 + ... + 6440.

It is an arithmetic number, because the mean of its divisors is an integer number (1218420).

Almost surely, 2^20535540 is an apocalyptic number.

20535540 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 20535540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29242080).

20535540 is an abundant number, since it is smaller than the sum of its proper divisors (37948620).

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

20535540 is a wasteful number, since it uses less digits than its factorization.

20535540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5872 (or 5870 counting only the distinct ones).

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

The square root of 20535540 is about 4531.6156059401. The cubic root of 20535540 is about 273.8432513151.

It can be divided in two parts, 20535 and 540, that multiplied together give a square (11088900 = 3330²).

The spelling of 20535540 in words is "twenty million, five hundred thirty-five thousand, five hundred forty".