648805649 has 4 divisors (see below), whose sum is σ = 649230960. Its totient is φ = 648380340.

The previous prime is 648805637. The next prime is 648805657. The reversal of 648805649 is 946508846.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 946508846 = 2 ⋅473254423.

It is a cyclic number.

It is not a de Polignac number, because 648805649 - 2⁸ = 648805393 is a prime.

It is a super-2 number, since 2×648805649² = 841897540348622402, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 648805597 and 648805606.

It is not an unprimeable number, because it can be changed into a prime (648805669) 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 in 3 ways as a sum of consecutive naturals, for example, 210359 + ... + 213420.

It is an arithmetic number, because the mean of its divisors is an integer number (162307740).

Almost surely, 2^648805649 is an apocalyptic number.

It is an amenable number.

648805649 is a deficient number, since it is larger than the sum of its proper divisors (425311).

648805649 is a wasteful number, since it uses less digits than its factorization.

648805649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425310.

The product of its (nonzero) digits is 1658880, while the sum is 50.

The square root of 648805649 is about 25471.6636480619. The cubic root of 648805649 is about 865.7082192562.

The spelling of 648805649 in words is "six hundred forty-eight million, eight hundred five thousand, six hundred forty-nine".