25891840 has 88 divisors (see below), whose sum is σ = 67059720. Its totient is φ = 9535488.

The previous prime is 25891777. The next prime is 25891841. The reversal of 25891840 is 4819852.

It can be written as a sum of positive squares in 4 ways, for example, as 4096 + 25887744 = 64^2 + 5088^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25891840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25891841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66366 + ... + 66754.

Almost surely, 2^25891840 is an apocalyptic number.

25891840 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 25891840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33529860).

25891840 is an abundant number, since it is smaller than the sum of its proper divisors (41167880).

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

25891840 is a wasteful number, since it uses less digits than its factorization.

25891840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 409 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 25891840 is about 5088.4024998029. The cubic root of 25891840 is about 295.8382364238.

The spelling of 25891840 in words is "twenty-five million, eight hundred ninety-one thousand, eight hundred forty".