25198640 has 20 divisors (see below), whose sum is σ = 58587024. Its totient is φ = 10079424.

The previous prime is 25198609. The next prime is 25198703. The reversal of 25198640 is 4689152.

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 25198640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157412 + ... + 157571.

Almost surely, 2^25198640 is an apocalyptic number.

25198640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25198640 is an abundant number, since it is smaller than the sum of its proper divisors (33388384).

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

25198640 is a wasteful number, since it uses less digits than its factorization.

25198640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314996 (or 314990 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 25198640 is about 5019.8246981344. The cubic root of 25198640 is about 293.1741675532.

The spelling of 25198640 in words is "twenty-five million, one hundred ninety-eight thousand, six hundred forty".