649558109 has 2 divisors, whose sum is σ = 649558110. Its totient is φ = 649558108.

The previous prime is 649558103. The next prime is 649558163. The reversal of 649558109 is 901855946.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 355435609 + 294122500 = 18853^2 + 17150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649558109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649558103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324779054 + 324779055.

It is an arithmetic number, because the mean of its divisors is an integer number (324779055).

Almost surely, 2^649558109 is an apocalyptic number.

It is an amenable number.

649558109 is a deficient number, since it is larger than the sum of its proper divisors (1).

649558109 is an equidigital number, since it uses as much as digits as its factorization.

649558109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 388800, while the sum is 47.

The square root of 649558109 is about 25486.4298990659. The cubic root of 649558109 is about 866.0427617306.

The spelling of 649558109 in words is "six hundred forty-nine million, five hundred fifty-eight thousand, one hundred nine".