25436336640 has 1280 divisors, whose sum is σ = 106913157120. Its totient is φ = 5060689920.

The previous prime is 25436336623. The next prime is 25436336641. The reversal of 25436336640 is 4663363452.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a junction number, because it is equal to n+sod(n) for n = 25436336592 and 25436336601.

It is not an unprimeable number, because it can be changed into a prime (25436336641) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 479930854 + ... + 479930906.

It is an arithmetic number, because the mean of its divisors is an integer number (83525904).

Almost surely, 2^25436336640 is an apocalyptic number.

25436336640 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 25436336640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53456578560).

25436336640 is an abundant number, since it is smaller than the sum of its proper divisors (81476820480).

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

25436336640 is a wasteful number, since it uses less digits than its factorization.

25436336640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 42.

The spelling of 25436336640 in words is "twenty-five billion, four hundred thirty-six million, three hundred thirty-six thousand, six hundred forty".