25221 has 8 divisors (see below), whose sum is σ = 38464. Its totient is φ = 14400.

The previous prime is 25219. The next prime is 25229. The reversal of 25221 is 12252.

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

It is not a de Polignac number, because 25221 - 2¹ = 25219 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 25197 and 25206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 580 + ... + 621.

It is an arithmetic number, because the mean of its divisors is an integer number (4808).

2²⁵²²¹ is an apocalyptic number.

25221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25221 is a deficient number, since it is larger than the sum of its proper divisors (13243).

25221 is a wasteful number, since it uses less digits than its factorization.

25221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1211.

The product of its digits is 40, while the sum is 12.

The square root of 25221 is about 158.8112086724. The cubic root of 25221 is about 29.3260857898.

Adding to 25221 its reverse (12252), we get a palindrome (37473).

The spelling of 25221 in words is "twenty-five thousand, two hundred twenty-one".