25543626640 has 80 divisors (see below), whose sum is σ = 67936901760. Its totient is φ = 8749578240.

The previous prime is 25543626637. The next prime is 25543626671. The reversal of 25543626640 is 4662634552.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 590056 + ... + 631864.

It is an arithmetic number, because the mean of its divisors is an integer number (849211272).

Almost surely, 2^25543626640 is an apocalyptic number.

25543626640 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 25543626640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33968450880).

25543626640 is an abundant number, since it is smaller than the sum of its proper divisors (42393275120).

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

25543626640 is a wasteful number, since it uses less digits than its factorization.

25543626640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42920 (or 42914 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 43.

The spelling of 25543626640 in words is "twenty-five billion, five hundred forty-three million, six hundred twenty-six thousand, six hundred forty".