20553500 has 96 divisors (see below), whose sum is σ = 50791104. Its totient is φ = 7200000.

The previous prime is 20553499. The next prime is 20553503. The reversal of 20553500 is 535502.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20553503) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 203450 + ... + 203550.

It is an arithmetic number, because the mean of its divisors is an integer number (529074).

Almost surely, 2^20553500 is an apocalyptic number.

20553500 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 20553500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25395552).

20553500 is an abundant number, since it is smaller than the sum of its proper divisors (30237604).

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

20553500 is a wasteful number, since it uses less digits than its factorization.

20553500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 20.

The square root of 20553500 is about 4533.5968060691. The cubic root of 20553500 is about 273.9230607851.

It can be divided in two parts, 2055 and 3500, that added together give a palindrome (5555).

The spelling of 20553500 in words is "twenty million, five hundred fifty-three thousand, five hundred".