25689840 has 160 divisors (see below), whose sum is σ = 89565696. Its totient is φ = 6036480.

The previous prime is 25689809. The next prime is 25689869. The reversal of 25689840 is 4898652.

It is a junction number, because it is equal to n+sod(n) for n = 25689792 and 25689801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97549 + ... + 97811.

Almost surely, 2^25689840 is an apocalyptic number.

25689840 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 25689840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44782848).

25689840 is an abundant number, since it is smaller than the sum of its proper divisors (63875856).

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

25689840 is a wasteful number, since it uses less digits than its factorization.

25689840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 25689840 is about 5068.5145752972. The cubic root of 25689840 is about 295.0668813214.

The spelling of 25689840 in words is "twenty-five million, six hundred eighty-nine thousand, eight hundred forty".