20253240 has 320 divisors, whose sum is σ = 83635200. Its totient is φ = 4292352.

The previous prime is 20253209. The next prime is 20253241. The reversal of 20253240 is 4235202.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20253241) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 430897 + ... + 430943.

It is an arithmetic number, because the mean of its divisors is an integer number (261360).

Almost surely, 2^20253240 is an apocalyptic number.

20253240 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 20253240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41817600).

20253240 is an abundant number, since it is smaller than the sum of its proper divisors (63381960).

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

20253240 is a wasteful number, since it uses less digits than its factorization.

20253240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 18.

The square root of 20253240 is about 4500.3599856012. The cubic root of 20253240 is about 272.5826251143.

Adding to 20253240 its reverse (4235202), we get a palindrome (24488442).

The spelling of 20253240 in words is "twenty million, two hundred fifty-three thousand, two hundred forty".