20553240 has 64 divisors (see below), whose sum is σ = 62726400. Its totient is φ = 5386112.

The previous prime is 20553227. The next prime is 20553251. The reversal of 20553240 is 4235502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5629 + ... + 8531.

It is an arithmetic number, because the mean of its divisors is an integer number (980100).

Almost surely, 2^20553240 is an apocalyptic number.

20553240 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 20553240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31363200).

20553240 is an abundant number, since it is smaller than the sum of its proper divisors (42173160).

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

20553240 is a wasteful number, since it uses less digits than its factorization.

20553240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2976 (or 2972 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 21.

The square root of 20553240 is about 4533.5681311744. The cubic root of 20553240 is about 273.9219057459.

Adding to 20553240 its reverse (4235502), we get a palindrome (24788742).

The spelling of 20553240 in words is "twenty million, five hundred fifty-three thousand, two hundred forty".