25151221 has 2 divisors, whose sum is σ = 25151222. Its totient is φ = 25151220.

The previous prime is 25151209. The next prime is 25151233. The reversal of 25151221 is 12215152.

It is a balanced prime because it is at equal distance from previous prime (25151209) and next prime (25151233).

It can be written as a sum of positive squares in only one way, i.e., 25140196 + 11025 = 5014^2 + 105^2 .

It is a cyclic number.

It is not a de Polignac number, because 25151221 - 2⁹ = 25150709 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25151281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12575610 + 12575611.

It is an arithmetic number, because the mean of its divisors is an integer number (12575611).

Almost surely, 2^25151221 is an apocalyptic number.

It is an amenable number.

25151221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25151221 is an equidigital number, since it uses as much as digits as its factorization.

25151221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 200, while the sum is 19.

The square root of 25151221 is about 5015.0993011106. The cubic root of 25151221 is about 292.9901529226.

Adding to 25151221 its reverse (12215152), we get a palindrome (37366373).

The spelling of 25151221 in words is "twenty-five million, one hundred fifty-one thousand, two hundred twenty-one".