25502717440 has 80 divisors (see below), whose sum is σ = 61245798768. Its totient is φ = 10184564736.

The previous prime is 25502717419. The next prime is 25502717447. The reversal of 25502717440 is 4471720552.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 25502717440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25502717447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1638334 + ... + 1653826.

Almost surely, 2^25502717440 is an apocalyptic number.

25502717440 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 25502717440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30622899384).

25502717440 is an abundant number, since it is smaller than the sum of its proper divisors (35743081328).

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

25502717440 is an equidigital number, since it uses as much as digits as its factorization.

25502717440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16159 (or 16143 counting only the distinct ones).

The product of its (nonzero) digits is 78400, while the sum is 37.

The spelling of 25502717440 in words is "twenty-five billion, five hundred two million, seven hundred seventeen thousand, four hundred forty".