645634210 has 32 divisors (see below), whose sum is σ = 1291917312. Its totient is φ = 230696640.

The previous prime is 645634189. The next prime is 645634243. The reversal of 645634210 is 12436546.

645634210 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76074 + ... + 84133.

It is an arithmetic number, because the mean of its divisors is an integer number (40372416).

Almost surely, 2^645634210 is an apocalyptic number.

645634210 is an abundant number, since it is smaller than the sum of its proper divisors (646283102).

645634210 is a wasteful number, since it uses less digits than its factorization.

645634210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160258.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 645634210 is about 25409.3331278096. Note that the first 3 decimals coincide. The cubic root of 645634210 is about 864.2953531633.

The spelling of 645634210 in words is "six hundred forty-five million, six hundred thirty-four thousand, two hundred ten".