25817217120 has 144 divisors (see below), whose sum is σ = 88222260672. Its totient is φ = 6875136000.

The previous prime is 25817217113. The next prime is 25817217163. The reversal of 25817217120 is 2171271852.

25817217120 is a `hidden beast` number, since 2 + 581 + 7 + 2 + 1 + 71 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1069504 + ... + 1093376.

It is an arithmetic number, because the mean of its divisors is an integer number (612654588).

Almost surely, 2^25817217120 is an apocalyptic number.

25817217120 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 25817217120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44111130336).

25817217120 is an abundant number, since it is smaller than the sum of its proper divisors (62405043552).

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

25817217120 is a wasteful number, since it uses less digits than its factorization.

25817217120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24645 (or 24634 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 36.

Adding to 25817217120 its reverse (2171271852), we get a palindrome (27988488972).

The spelling of 25817217120 in words is "twenty-five billion, eight hundred seventeen million, two hundred seventeen thousand, one hundred twenty".