20252440 has 128 divisors (see below), whose sum is σ = 54432000. Its totient is φ = 6709248.

The previous prime is 20252381. The next prime is 20252447. The reversal of 20252440 is 4425202.

It is a super-2 number, since 2×20252440² = 820322651907200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20252447) 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, 256321 + ... + 256399.

It is an arithmetic number, because the mean of its divisors is an integer number (425250).

Almost surely, 2^20252440 is an apocalyptic number.

20252440 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 20252440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27216000).

20252440 is an abundant number, since it is smaller than the sum of its proper divisors (34179560).

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

20252440 is a wasteful number, since it uses less digits than its factorization.

20252440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 19.

The square root of 20252440 is about 4500.2711029448. The cubic root of 20252440 is about 272.5790360759.

Adding to 20252440 its reverse (4425202), we get a palindrome (24677642).

It can be divided in two parts, 2025 and 2440, that added together give a triangular number (4465 = T₉₄).

The spelling of 20252440 in words is "twenty million, two hundred fifty-two thousand, four hundred forty".