647640305 has 32 divisors (see below), whose sum is σ = 869369760. Its totient is φ = 460062720.

The previous prime is 647640299. The next prime is 647640319. The reversal of 647640305 is 503046746.

647640305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 16 ways, for example, as 436141456 + 211498849 = 20884^2 + 14543^2 .

It is not a de Polignac number, because 647640305 - 2¹⁸ = 647378161 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 192881 + ... + 196209.

It is an arithmetic number, because the mean of its divisors is an integer number (27167805).

Almost surely, 2^647640305 is an apocalyptic number.

647640305 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

647640305 is a deficient number, since it is larger than the sum of its proper divisors (221729455).

647640305 is a wasteful number, since it uses less digits than its factorization.

647640305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3461.

The product of its (nonzero) digits is 60480, while the sum is 35.

The square root of 647640305 is about 25448.7780649681. The cubic root of 647640305 is about 865.1895983647.

The spelling of 647640305 in words is "six hundred forty-seven million, six hundred forty thousand, three hundred five".