645556198 has 32 divisors (see below), whose sum is σ = 1233446400. Its totient is φ = 246685824.

The previous prime is 645556151. The next prime is 645556201. The reversal of 645556198 is 891655546.

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, 66858 + ... + 75901.

It is an arithmetic number, because the mean of its divisors is an integer number (38545200).

Almost surely, 2^645556198 is an apocalyptic number.

645556198 is a deficient number, since it is larger than the sum of its proper divisors (587890202).

645556198 is a wasteful number, since it uses less digits than its factorization.

645556198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142804.

The product of its digits is 1296000, while the sum is 49.

The square root of 645556198 is about 25407.7979762119. The cubic root of 645556198 is about 864.2605408171.

The spelling of 645556198 in words is "six hundred forty-five million, five hundred fifty-six thousand, one hundred ninety-eight".