25701221 has 16 divisors (see below), whose sum is σ = 32726400. Its totient is φ = 19631808.

The previous prime is 25701173. The next prime is 25701227. The reversal of 25701221 is 12210752.

It is a de Polignac number, because none of the positive numbers 2^k-25701221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25701193 and 25701202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25701227) 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, 2231 + ... + 7508.

It is an arithmetic number, because the mean of its divisors is an integer number (2045400).

Almost surely, 2^25701221 is an apocalyptic number.

It is an amenable number.

25701221 is a deficient number, since it is larger than the sum of its proper divisors (7025179).

25701221 is a wasteful number, since it uses less digits than its factorization.

25701221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9788.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 25701221 is about 5069.6371665041. The cubic root of 25701221 is about 295.1104479661.

Adding to 25701221 its reverse (12210752), we get a palindrome (37911973).

The spelling of 25701221 in words is "twenty-five million, seven hundred one thousand, two hundred twenty-one".