25215500 has 96 divisors (see below), whose sum is σ = 59754240. Its totient is φ = 9273600.

The previous prime is 25215499. The next prime is 25215503. The reversal of 25215500 is 551252.

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

It is not an unprimeable number, because it can be changed into a prime (25215503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 536477 + ... + 536523.

It is an arithmetic number, because the mean of its divisors is an integer number (622440).

Almost surely, 2^25215500 is an apocalyptic number.

25215500 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 25215500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29877120).

25215500 is an abundant number, since it is smaller than the sum of its proper divisors (34538740).

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

25215500 is a wasteful number, since it uses less digits than its factorization.

25215500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 25215500 is about 5021.5037588356. The cubic root of 25215500 is about 293.2395389974.

Adding to 25215500 its reverse (551252), we get a palindrome (25766752).

The spelling of 25215500 in words is "twenty-five million, two hundred fifteen thousand, five hundred".