25128640 has 56 divisors (see below), whose sum is σ = 63002160. Its totient is φ = 9520128.

The previous prime is 25128619. The next prime is 25128643. The reversal of 25128640 is 4682152.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 25128599 and 25128608.

It is not an unprimeable number, because it can be changed into a prime (25128643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4014 + ... + 8146.

Almost surely, 2^25128640 is an apocalyptic number.

25128640 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 25128640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31501080).

25128640 is an abundant number, since it is smaller than the sum of its proper divisors (37873520).

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

25128640 is a wasteful number, since it uses less digits than its factorization.

25128640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4169 (or 4159 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 25128640 is about 5012.8474941893. The cubic root of 25128640 is about 292.9024435744.

The spelling of 25128640 in words is "twenty-five million, one hundred twenty-eight thousand, six hundred forty".