645379198 has 8 divisors (see below), whose sum is σ = 986334408. Its totient is φ = 316601064.

The previous prime is 645379187. The next prime is 645379201. The reversal of 645379198 is 891973546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×645379198² = 833028618422246408, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3044136 + ... + 3044347.

It is an arithmetic number, because the mean of its divisors is an integer number (123291801).

Almost surely, 2^645379198 is an apocalyptic number.

645379198 is a deficient number, since it is larger than the sum of its proper divisors (340955210).

645379198 is a wasteful number, since it uses less digits than its factorization.

645379198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6088538.

The product of its digits is 1632960, while the sum is 52.

The square root of 645379198 is about 25404.3145548153. The cubic root of 645379198 is about 864.1815453198.

The spelling of 645379198 in words is "six hundred forty-five million, three hundred seventy-nine thousand, one hundred ninety-eight".