25559324640 has 144 divisors (see below), whose sum is σ = 87635607696. Its totient is φ = 6783436800.

The previous prime is 25559324639. The next prime is 25559324671. The reversal of 25559324640 is 4642395552.

25559324640 is a `hidden beast` number, since 2 + 5 + 559 + 32 + 4 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×25559324640² (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 a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 261780 + ... + 345900.

It is an arithmetic number, because the mean of its divisors is an integer number (608580609).

Almost surely, 2^25559324640 is an apocalyptic number.

25559324640 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 25559324640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43817803848).

25559324640 is an abundant number, since it is smaller than the sum of its proper divisors (62076283056).

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

25559324640 is a wasteful number, since it uses less digits than its factorization.

25559324640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84353 (or 84342 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 45.

The spelling of 25559324640 in words is "twenty-five billion, five hundred fifty-nine million, three hundred twenty-four thousand, six hundred forty".