25081221 has 32 divisors (see below), whose sum is σ = 37859328. Its totient is φ = 14639040.

The previous prime is 25081213. The next prime is 25081241. The reversal of 25081221 is 12218052.

It is a happy number.

It is not a de Polignac number, because 25081221 - 2³ = 25081213 is a prime.

It is a super-3 number, since 3×25081221³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25081241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159675 + ... + 159831.

It is an arithmetic number, because the mean of its divisors is an integer number (1183104).

Almost surely, 2^25081221 is an apocalyptic number.

It is an amenable number.

25081221 is a deficient number, since it is larger than the sum of its proper divisors (12778107).

25081221 is a wasteful number, since it uses less digits than its factorization.

25081221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 25081221 is about 5008.1155138435. The cubic root of 25081221 is about 292.7180870441.

Adding to 25081221 its reverse (12218052), we get a palindrome (37299273).

The spelling of 25081221 in words is "twenty-five million, eighty-one thousand, two hundred twenty-one".