25720240 has 80 divisors (see below), whose sum is σ = 73620288. Its totient is φ = 8137728.

The previous prime is 25720213. The next prime is 25720241. The reversal of 25720240 is 4202752.

25720240 = 442² + 443² + ... + 546².

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 (25720241) 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, 5514 + ... + 9046.

Almost surely, 2^25720240 is an apocalyptic number.

25720240 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 25720240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36810144).

25720240 is an abundant number, since it is smaller than the sum of its proper divisors (47900048).

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

25720240 is a wasteful number, since it uses less digits than its factorization.

25720240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3566 (or 3560 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 22.

The square root of 25720240 is about 5071.5125948774. The cubic root of 25720240 is about 295.1832242972.

Adding to 25720240 its reverse (4202752), we get a palindrome (29922992).

The spelling of 25720240 in words is "twenty-five million, seven hundred twenty thousand, two hundred forty".