249401221 has 2 divisors, whose sum is σ = 249401222. Its totient is φ = 249401220.

The previous prime is 249401197. The next prime is 249401227. The reversal of 249401221 is 122104942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128709025 + 120692196 = 11345^2 + 10986^2 .

It is a cyclic number.

It is not a de Polignac number, because 249401221 - 2¹¹ = 249399173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249401227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124700610 + 124700611.

It is an arithmetic number, because the mean of its divisors is an integer number (124700611).

Almost surely, 2^249401221 is an apocalyptic number.

It is an amenable number.

249401221 is a deficient number, since it is larger than the sum of its proper divisors (1).

249401221 is an equidigital number, since it uses as much as digits as its factorization.

249401221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 249401221 is about 15792.4418947799. The cubic root of 249401221 is about 629.4571800326.

The spelling of 249401221 in words is "two hundred forty-nine million, four hundred one thousand, two hundred twenty-one".