645804198 has 32 divisors (see below), whose sum is σ = 1545516000. Its totient is φ = 198708768.

The previous prime is 645804169. The next prime is 645804217. The reversal of 645804198 is 891408546.

645804198 is a `hidden beast` number, since 6 + 458 + 0 + 4 + 198 = 666.

645804198 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 459273 + ... + 460676.

It is an arithmetic number, because the mean of its divisors is an integer number (48297375).

Almost surely, 2^645804198 is an apocalyptic number.

645804198 is an abundant number, since it is smaller than the sum of its proper divisors (899711802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645804198 is a wasteful number, since it uses less digits than its factorization.

645804198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 919973 (or 919967 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 645804198 is about 25412.6778990330. The cubic root of 645804198 is about 864.3711994883.

The spelling of 645804198 in words is "six hundred forty-five million, eight hundred four thousand, one hundred ninety-eight".