25543221 has 16 divisors (see below), whose sum is σ = 37466688. Its totient is φ = 15478320.

The previous prime is 25543187. The next prime is 25543223. The reversal of 25543221 is 12234552.

It is not a de Polignac number, because 25543221 - 2⁷ = 25543093 is a prime.

It is a super-2 number, since 2×25543221² = 1304912278109682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25543191 and 25543200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25543223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 795 + ... + 7191.

It is an arithmetic number, because the mean of its divisors is an integer number (2341668).

Almost surely, 2^25543221 is an apocalyptic number.

It is an amenable number.

25543221 is a deficient number, since it is larger than the sum of its proper divisors (11923467).

25543221 is an equidigital number, since it uses as much as digits as its factorization.

25543221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6433 (or 6411 counting only the distinct ones).

The product of its digits is 2400, while the sum is 24.

The square root of 25543221 is about 5054.0301740294. The cubic root of 25543221 is about 294.5044673278.

Adding to 25543221 its reverse (12234552), we get a palindrome (37777773).

It can be divided in two parts, 2554 and 3221, that added together give a palindrome (5775).

The spelling of 25543221 in words is "twenty-five million, five hundred forty-three thousand, two hundred twenty-one".