25766640 has 160 divisors (see below), whose sum is σ = 90470400. Its totient is φ = 6739200.

The previous prime is 25766633. The next prime is 25766651. The reversal of 25766640 is 4666752.

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 = 25766595 and 25766604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 170565 + ... + 170715.

It is an arithmetic number, because the mean of its divisors is an integer number (565440).

Almost surely, 2^25766640 is an apocalyptic number.

25766640 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 25766640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45235200).

25766640 is an abundant number, since it is smaller than the sum of its proper divisors (64703760).

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

25766640 is a wasteful number, since it uses less digits than its factorization.

25766640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 25766640 is about 5076.0851056695. The cubic root of 25766640 is about 295.3606238026.

It can be divided in two parts, 2576 and 6640, that added together give a square (9216 = 96²).

The spelling of 25766640 in words is "twenty-five million, seven hundred sixty-six thousand, six hundred forty".