249864557855557 has 2 divisors, whose sum is σ = 249864557855558. Its totient is φ = 249864557855556.

The previous prime is 249864557855531. The next prime is 249864557855567. The reversal of 249864557855557 is 755558755468942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249795780695041 + 68777160516 = 15804929^2 + 262254^2 .

It is a cyclic number.

It is not a de Polignac number, because 249864557855557 - 2¹¹ = 249864557853509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249864557855527) 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, 124932278927778 + 124932278927779.

It is an arithmetic number, because the mean of its divisors is an integer number (124932278927779).

Almost surely, 2^{249864557855557} is an apocalyptic number.

It is an amenable number.

249864557855557 is a deficient number, since it is larger than the sum of its proper divisors (1).

249864557855557 is an equidigital number, since it uses as much as digits as its factorization.

249864557855557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672000000, while the sum is 85.

The spelling of 249864557855557 in words is "two hundred forty-nine trillion, eight hundred sixty-four billion, five hundred fifty-seven million, eight hundred fifty-five thousand, five hundred fifty-seven".