25520447 has 4 divisors (see below), whose sum is σ = 25632120. Its totient is φ = 25408776.

The previous prime is 25520437. The next prime is 25520479. The reversal of 25520447 is 74402552.

It is a happy number.

25520447 is nontrivially palindromic in base 15.

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

It is a cyclic number.

It is not a de Polignac number, because 25520447 - 2⁸ = 25520191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25520437) 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, 55493 + ... + 55950.

It is an arithmetic number, because the mean of its divisors is an integer number (6408030).

Almost surely, 2^25520447 is an apocalyptic number.

25520447 is a deficient number, since it is larger than the sum of its proper divisors (111673).

25520447 is a wasteful number, since it uses less digits than its factorization.

25520447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111672.

The product of its (nonzero) digits is 11200, while the sum is 29.

The square root of 25520447 is about 5051.7766181810. The cubic root of 25520447 is about 294.4169158658.

Adding to 25520447 its reverse (74402552), we get a palindrome (99922999).

It can be divided in two parts, 255 and 20447, that added together give a palindrome (20702).

The spelling of 25520447 in words is "twenty-five million, five hundred twenty thousand, four hundred forty-seven".