25665840 has 120 divisors (see below), whose sum is σ = 88305360. Its totient is φ = 6676992.

The previous prime is 25665839. The next prime is 25665859. The reversal of 25665840 is 4856652.

25665840 is a `hidden beast` number, since 2 + 566 + 58 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 25665795 and 25665804.

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, 30546 + ... + 31374.

It is an arithmetic number, because the mean of its divisors is an integer number (735878).

Almost surely, 2^25665840 is an apocalyptic number.

25665840 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 25665840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44152680).

25665840 is an abundant number, since it is smaller than the sum of its proper divisors (62639520).

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

25665840 is a wasteful number, since it uses less digits than its factorization.

25665840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891 (or 882 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 25665840 is about 5066.1464645231. The cubic root of 25665840 is about 294.9749667545.

The spelling of 25665840 in words is "twenty-five million, six hundred sixty-five thousand, eight hundred forty".