25028809 has 4 divisors (see below), whose sum is σ = 26954116. Its totient is φ = 23103504.

The previous prime is 25028771. The next prime is 25028821. The reversal of 25028809 is 90882052.

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 1960000 + 23068809 = 1400^2 + 4803^2 .

It is a cyclic number.

It is not a de Polignac number, because 25028809 - 2¹⁹ = 24504521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25028009) 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, 962634 + ... + 962659.

It is an arithmetic number, because the mean of its divisors is an integer number (6738529).

Almost surely, 2^25028809 is an apocalyptic number.

It is an amenable number.

25028809 is a deficient number, since it is larger than the sum of its proper divisors (1925307).

25028809 is a wasteful number, since it uses less digits than its factorization.

25028809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1925306.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 25028809 is about 5002.8800705194. The cubic root of 25028809 is about 292.5140480749.

It can be divided in two parts, 2502 and 8809, that added together give a palindrome (11311).

The spelling of 25028809 in words is "twenty-five million, twenty-eight thousand, eight hundred nine".