25980721 has 4 divisors (see below), whose sum is σ = 27979252. Its totient is φ = 23982192.

The previous prime is 25980719. The next prime is 25980727. The reversal of 25980721 is 12708952.

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 1527696 + 24453025 = 1236^2 + 4945^2 .

It is not a de Polignac number, because 25980721 - 2¹ = 25980719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25980727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999246 + ... + 999271.

It is an arithmetic number, because the mean of its divisors is an integer number (6994813).

Almost surely, 2^25980721 is an apocalyptic number.

It is an amenable number.

25980721 is a deficient number, since it is larger than the sum of its proper divisors (1998531).

25980721 is a wasteful number, since it uses less digits than its factorization.

25980721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1998530.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 25980721 is about 5097.1287015338. The cubic root of 25980721 is about 296.1763657072.

The spelling of 25980721 in words is "twenty-five million, nine hundred eighty thousand, seven hundred twenty-one".