249161657 has 2 divisors, whose sum is σ = 249161658. Its totient is φ = 249161656.

The previous prime is 249161597. The next prime is 249161659. The reversal of 249161657 is 756161942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180338041 + 68823616 = 13429^2 + 8296^2 .

It is a cyclic number.

It is not a de Polignac number, because 249161657 - 2¹² = 249157561 is a prime.

Together with 249161659, 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 (249161659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124580828 + 124580829.

It is an arithmetic number, because the mean of its divisors is an integer number (124580829).

Almost surely, 2^249161657 is an apocalyptic number.

It is an amenable number.

249161657 is a deficient number, since it is larger than the sum of its proper divisors (1).

249161657 is an equidigital number, since it uses as much as digits as its factorization.

249161657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 249161657 is about 15784.8553050068. The cubic root of 249161657 is about 629.2555723747.

The spelling of 249161657 in words is "two hundred forty-nine million, one hundred sixty-one thousand, six hundred fifty-seven".