25720221 has 8 divisors (see below), whose sum is σ = 34431264. Its totient is φ = 17078000.

The previous prime is 25720213. The next prime is 25720241. The reversal of 25720221 is 12202752.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25720221 - 2³ = 25720213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25720241) 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 7 ways as a sum of consecutive naturals, for example, 16326 + ... + 17831.

It is an arithmetic number, because the mean of its divisors is an integer number (4303908).

Almost surely, 2^25720221 is an apocalyptic number.

It is an amenable number.

25720221 is a deficient number, since it is larger than the sum of its proper divisors (8711043).

25720221 is a wasteful number, since it uses less digits than its factorization.

25720221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34411.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 25720221 is about 5071.5107216686. The cubic root of 25720221 is about 295.1831516115.

Adding to 25720221 its reverse (12202752), we get a palindrome (37922973).

The spelling of 25720221 in words is "twenty-five million, seven hundred twenty thousand, two hundred twenty-one".