25820645 has 4 divisors (see below), whose sum is σ = 30984780. Its totient is φ = 20656512.

The previous prime is 25820623. The next prime is 25820659. The reversal of 25820645 is 54602852.

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 11930116 + 13890529 = 3454^2 + 3727^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25820645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2582060 + ... + 2582069.

It is an arithmetic number, because the mean of its divisors is an integer number (7746195).

Almost surely, 2^25820645 is an apocalyptic number.

It is an amenable number.

25820645 is a deficient number, since it is larger than the sum of its proper divisors (5164135).

25820645 is an equidigital number, since it uses as much as digits as its factorization.

25820645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5164134.

The product of its (nonzero) digits is 19200, while the sum is 32.

The square root of 25820645 is about 5081.4018734991. The cubic root of 25820645 is about 295.5668312532.

The spelling of 25820645 in words is "twenty-five million, eight hundred twenty thousand, six hundred forty-five".