25820100 has 144 divisors (see below), whose sum is σ = 84786240. Its totient is φ = 6739200.

The previous prime is 25820087. The next prime is 25820101. The reversal of 25820100 is 102852.

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

It is not an unprimeable number, because it can be changed into a prime (25820101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 197035 + ... + 197165.

Almost surely, 2^25820100 is an apocalyptic number.

25820100 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 25820100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42393120).

25820100 is an abundant number, since it is smaller than the sum of its proper divisors (58966140).

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

25820100 is a wasteful number, since it uses less digits than its factorization.

25820100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 25820100 is about 5081.3482462827. The cubic root of 25820100 is about 295.5647517150.

Adding to 25820100 its reverse (102852), we get a palindrome (25922952).

The spelling of 25820100 in words is "twenty-five million, eight hundred twenty thousand, one hundred".