25408880640 has 720 divisors, whose sum is σ = 103909661856. Its totient is φ = 5662310400.

The previous prime is 25408880621. The next prime is 25408880657. The reversal of 25408880640 is 4608880452.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×25408880640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 105430920 + ... + 105431160.

Almost surely, 2^25408880640 is an apocalyptic number.

25408880640 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 25408880640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51954830928).

25408880640 is an abundant number, since it is smaller than the sum of its proper divisors (78500781216).

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

25408880640 is a wasteful number, since it uses less digits than its factorization.

25408880640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 25408880640 in words is "twenty-five billion, four hundred eight million, eight hundred eighty thousand, six hundred forty".