249866305520809 has 2 divisors, whose sum is σ = 249866305520810. Its totient is φ = 249866305520808.

The previous prime is 249866305520723. The next prime is 249866305520879. The reversal of 249866305520809 is 908025503668942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176105639430400 + 73760666090409 = 13270480^2 + 8588403^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249866305520809 is a prime.

It is not a weakly prime, because it can be changed into another prime (249866305520879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124933152760404 + 124933152760405.

It is an arithmetic number, because the mean of its divisors is an integer number (124933152760405).

Almost surely, 2^{249866305520809} is an apocalyptic number.

It is an amenable number.

249866305520809 is a deficient number, since it is larger than the sum of its proper divisors (1).

249866305520809 is an equidigital number, since it uses as much as digits as its factorization.

249866305520809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 223948800, while the sum is 67.

The spelling of 249866305520809 in words is "two hundred forty-nine trillion, eight hundred sixty-six billion, three hundred five million, five hundred twenty thousand, eight hundred nine".