25280640 has 512 divisors, whose sum is σ = 117504000. Its totient is φ = 4976640.

The previous prime is 25280639. The next prime is 25280653. The reversal of 25280640 is 4608252.

It is a super-2 number, since 2×25280640² = 1278221517619200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1330551 + ... + 1330569.

It is an arithmetic number, because the mean of its divisors is an integer number (229500).

Almost surely, 2^25280640 is an apocalyptic number.

25280640 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 25280640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58752000).

25280640 is an abundant number, since it is smaller than the sum of its proper divisors (92223360).

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

25280640 is a wasteful number, since it uses less digits than its factorization.

25280640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 25280640 is about 5027.9856801705. The cubic root of 25280640 is about 293.4918335322.

Adding to 25280640 its reverse (4608252), we get a palindrome (29888892).

The spelling of 25280640 in words is "twenty-five million, two hundred eighty thousand, six hundred forty".