25451440 has 80 divisors (see below), whose sum is σ = 69138432. Its totient is φ = 8531712.

The previous prime is 25451429. The next prime is 25451443. The reversal of 25451440 is 4415452.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (25451443) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 25837 + ... + 26803.

Almost surely, 2^25451440 is an apocalyptic number.

25451440 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 25451440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34569216).

25451440 is an abundant number, since it is smaller than the sum of its proper divisors (43686992).

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

25451440 is a wasteful number, since it uses less digits than its factorization.

25451440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 25.

The square root of 25451440 is about 5044.9420214706. The cubic root of 25451440 is about 294.1513096530.

Adding to 25451440 its reverse (4415452), we get a palindrome (29866892).

The spelling of 25451440 in words is "twenty-five million, four hundred fifty-one thousand, four hundred forty".