25405520 has 60 divisors (see below), whose sum is σ = 68722164. Its totient is φ = 8709120.

The previous prime is 25405519. The next prime is 25405571. The reversal of 25405520 is 2550452.

It can be written as a sum of positive squares in 2 ways, for example, as 17875984 + 7529536 = 4228^2 + 2744^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 680 + ... + 7160.

Almost surely, 2^25405520 is an apocalyptic number.

25405520 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 25405520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34361082).

25405520 is an abundant number, since it is smaller than the sum of its proper divisors (43316644).

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

25405520 is a wasteful number, since it uses less digits than its factorization.

25405520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6508 (or 6495 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 23.

The square root of 25405520 is about 5040.3888738866. The cubic root of 25405520 is about 293.9742985847.

Adding to 25405520 its reverse (2550452), we get a palindrome (27955972).

The spelling of 25405520 in words is "twenty-five million, four hundred five thousand, five hundred twenty".