25137221 has 2 divisors, whose sum is σ = 25137222. Its totient is φ = 25137220.

The previous prime is 25137199. The next prime is 25137227. The reversal of 25137221 is 12273152.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16900321 + 8236900 = 4111^2 + 2870^2 .

It is a cyclic number.

It is not a de Polignac number, because 25137221 - 2¹⁸ = 24875077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25137227) 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 as a sum of consecutive naturals, namely, 12568610 + 12568611.

It is an arithmetic number, because the mean of its divisors is an integer number (12568611).

Almost surely, 2^25137221 is an apocalyptic number.

It is an amenable number.

25137221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25137221 is an equidigital number, since it uses as much as digits as its factorization.

25137221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 25137221 is about 5013.7033218969. The cubic root of 25137221 is about 292.9357801687.

The spelling of 25137221 in words is "twenty-five million, one hundred thirty-seven thousand, two hundred twenty-one".