249661649 has 2 divisors, whose sum is σ = 249661650. Its totient is φ = 249661648.

The previous prime is 249661613. The next prime is 249661651. The reversal of 249661649 is 946166942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150798400 + 98863249 = 12280^2 + 9943^2 .

It is a cyclic number.

It is not a de Polignac number, because 249661649 - 2⁸ = 249661393 is a prime.

Together with 249661651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (249666649) 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, 124830824 + 124830825.

It is an arithmetic number, because the mean of its divisors is an integer number (124830825).

Almost surely, 2^249661649 is an apocalyptic number.

It is an amenable number.

249661649 is a deficient number, since it is larger than the sum of its proper divisors (1).

249661649 is an equidigital number, since it uses as much as digits as its factorization.

249661649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 559872, while the sum is 47.

The square root of 249661649 is about 15800.6850800843. The cubic root of 249661649 is about 629.6761996084.

The spelling of 249661649 in words is "two hundred forty-nine million, six hundred sixty-one thousand, six hundred forty-nine".