25404240 has 80 divisors (see below), whose sum is σ = 79387776. Its totient is φ = 6720000.

The previous prime is 25404233. The next prime is 25404241. The reversal of 25404240 is 4240452.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25404241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35890 + ... + 36590.

Almost surely, 2^25404240 is an apocalyptic number.

25404240 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 25404240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39693888).

25404240 is an abundant number, since it is smaller than the sum of its proper divisors (53983536).

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

25404240 is a wasteful number, since it uses less digits than its factorization.

25404240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868 (or 862 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 21.

The square root of 25404240 is about 5040.2618979573. The cubic root of 25404240 is about 293.9693614238.

Adding to 25404240 its reverse (4240452), we get a palindrome (29644692).

The spelling of 25404240 in words is "twenty-five million, four hundred four thousand, two hundred forty".