25978945 has 4 divisors (see below), whose sum is σ = 31174740. Its totient is φ = 20783152.

The previous prime is 25978933. The next prime is 25978949. The reversal of 25978945 is 54987952.

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 19430464 + 6548481 = 4408^2 + 2559^2 .

It is a cyclic number.

It is not a de Polignac number, because 25978945 - 2⁷ = 25978817 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (25978949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2597890 + ... + 2597899.

It is an arithmetic number, because the mean of its divisors is an integer number (7793685).

Almost surely, 2^25978945 is an apocalyptic number.

It is an amenable number.

25978945 is a deficient number, since it is larger than the sum of its proper divisors (5195795).

25978945 is an equidigital number, since it uses as much as digits as its factorization.

25978945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5195794.

The product of its digits is 907200, while the sum is 49.

The square root of 25978945 is about 5096.9544828260. The cubic root of 25978945 is about 296.1696168412.

The spelling of 25978945 in words is "twenty-five million, nine hundred seventy-eight thousand, nine hundred forty-five".