25281840 has 40 divisors (see below), whose sum is σ = 78374448. Its totient is φ = 6741760.

The previous prime is 25281827. The next prime is 25281869. The reversal of 25281840 is 4818252.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 25281798 and 25281807.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52431 + ... + 52910.

Almost surely, 2^25281840 is an apocalyptic number.

25281840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25281840 is an abundant number, since it is smaller than the sum of its proper divisors (53092608).

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

25281840 is a wasteful number, since it uses less digits than its factorization.

25281840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105357 (or 105351 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 25281840 is about 5028.1050108366. The cubic root of 25281840 is about 293.4964771993.

The spelling of 25281840 in words is "twenty-five million, two hundred eighty-one thousand, eight hundred forty".