25771221 has 24 divisors (see below), whose sum is σ = 42891264. Its totient is φ = 14605920.

The previous prime is 25771183. The next prime is 25771223. The reversal of 25771221 is 12217752.

It is not a de Polignac number, because 25771221 - 2⁶ = 25771157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25771223) 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 23 ways as a sum of consecutive naturals, for example, 6391 + ... + 9611.

It is an arithmetic number, because the mean of its divisors is an integer number (1787136).

Almost surely, 2^25771221 is an apocalyptic number.

25771221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25771221 is a deficient number, since it is larger than the sum of its proper divisors (17120043).

25771221 is a wasteful number, since it uses less digits than its factorization.

25771221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361 (or 3358 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 25771221 is about 5076.5363191846. The cubic root of 25771221 is about 295.3781266259.

Adding to 25771221 its reverse (12217752), we get a palindrome (37988973).

The spelling of 25771221 in words is "twenty-five million, seven hundred seventy-one thousand, two hundred twenty-one".