1649085209 has 2 divisors, whose sum is σ = 1649085210. Its totient is φ = 1649085208.

The previous prime is 1649085197. The next prime is 1649085239. The reversal of 1649085209 is 9025809461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 922944400 + 726140809 = 30380^2 + 26947^2 .

It is a cyclic number.

It is not a de Polignac number, because 1649085209 - 2⁸ = 1649084953 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1649085209.

It is not a weakly prime, because it can be changed into another prime (1649085239) 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, 824542604 + 824542605.

It is an arithmetic number, because the mean of its divisors is an integer number (824542605).

Almost surely, 2^1649085209 is an apocalyptic number.

It is an amenable number.

1649085209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649085209 is an equidigital number, since it uses as much as digits as its factorization.

1649085209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 1649085209 is about 40608.9301632043. The cubic root of 1649085209 is about 1181.4473308662.

The spelling of 1649085209 in words is "one billion, six hundred forty-nine million, eighty-five thousand, two hundred nine".