25400645 has 4 divisors (see below), whose sum is σ = 30480780. Its totient is φ = 20320512.

The previous prime is 25400629. The next prime is 25400647. The reversal of 25400645 is 54600452.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5987809 + 19412836 = 2447^2 + 4406^2 .

It is a cyclic number.

It is not a de Polignac number, because 25400645 - 2⁴ = 25400629 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25400647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2540060 + ... + 2540069.

It is an arithmetic number, because the mean of its divisors is an integer number (7620195).

Almost surely, 2^25400645 is an apocalyptic number.

It is an amenable number.

25400645 is a deficient number, since it is larger than the sum of its proper divisors (5080135).

25400645 is an equidigital number, since it uses as much as digits as its factorization.

25400645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5080134.

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 25400645 is about 5039.9052570460. The cubic root of 25400645 is about 293.9554940574.

The spelling of 25400645 in words is "twenty-five million, four hundred thousand, six hundred forty-five".