20204240 has 80 divisors (see below), whose sum is σ = 54341760. Its totient is φ = 6842880.

The previous prime is 20204231. The next prime is 20204243. The reversal of 20204240 is 4240202.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20204240² = 816422627955200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60875 + ... + 61205.

It is an arithmetic number, because the mean of its divisors is an integer number (679272).

Almost surely, 2^20204240 is an apocalyptic number.

20204240 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 20204240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27170880).

20204240 is an abundant number, since it is smaller than the sum of its proper divisors (34137520).

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

20204240 is a wasteful number, since it uses less digits than its factorization.

20204240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 20204240 is about 4494.9126799083. The cubic root of 20204240 is about 272.3626218854.

Adding to 20204240 its reverse (4240202), we get a palindrome (24444442).

The spelling of 20204240 in words is "twenty million, two hundred four thousand, two hundred forty".