649392509 has 2 divisors, whose sum is σ = 649392510. Its totient is φ = 649392508.

The previous prime is 649392487. The next prime is 649392533. The reversal of 649392509 is 905293946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 476548900 + 172843609 = 21830^2 + 13147^2 .

It is a cyclic number.

It is not a de Polignac number, because 649392509 - 2⁸ = 649392253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649392559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324696254 + 324696255.

It is an arithmetic number, because the mean of its divisors is an integer number (324696255).

Almost surely, 2^649392509 is an apocalyptic number.

It is an amenable number.

649392509 is a deficient number, since it is larger than the sum of its proper divisors (1).

649392509 is an equidigital number, since it uses as much as digits as its factorization.

649392509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 524880, while the sum is 47.

The square root of 649392509 is about 25483.1809042749. The cubic root of 649392509 is about 865.9691584257.

The spelling of 649392509 in words is "six hundred forty-nine million, three hundred ninety-two thousand, five hundred nine".