648445809 has 16 divisors (see below), whose sum is σ = 944187840. Its totient is φ = 392583360.

The previous prime is 648445781. The next prime is 648445823. The reversal of 648445809 is 908544846.

It is not a de Polignac number, because 648445809 - 2¹² = 648441713 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (648445849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23047 + ... + 42755.

It is an arithmetic number, because the mean of its divisors is an integer number (59011740).

Almost surely, 2^648445809 is an apocalyptic number.

It is an amenable number.

648445809 is a deficient number, since it is larger than the sum of its proper divisors (295742031).

648445809 is a wasteful number, since it uses less digits than its factorization.

648445809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20720.

The product of its (nonzero) digits is 1105920, while the sum is 48.

The square root of 648445809 is about 25464.5991329139. The cubic root of 648445809 is about 865.5481435567.

The spelling of 648445809 in words is "six hundred forty-eight million, four hundred forty-five thousand, eight hundred nine".