25205336640 has 336 divisors, whose sum is σ = 96135114816. Its totient is φ = 6009753600.

The previous prime is 25205336633. The next prime is 25205336641. The reversal of 25205336640 is 4663350252.

25205336640 is a `hidden beast` number, since 2 + 5 + 2 + 0 + 5 + 3 + 3 + 6 + 640 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 25205336595 and 25205336604.

It is not an unprimeable number, because it can be changed into a prime (25205336641) 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, 1925959 + ... + 1939001.

Almost surely, 2^25205336640 is an apocalyptic number.

25205336640 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 25205336640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48067557408).

25205336640 is an abundant number, since it is smaller than the sum of its proper divisors (70929778176).

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

25205336640 is a wasteful number, since it uses less digits than its factorization.

25205336640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13138 (or 13125 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

Adding to 25205336640 its reverse (4663350252), we get a palindrome (29868686892).

The spelling of 25205336640 in words is "twenty-five billion, two hundred five million, three hundred thirty-six thousand, six hundred forty".