643314194 has 4 divisors (see below), whose sum is σ = 964971294. Its totient is φ = 321657096.

The previous prime is 643314181. The next prime is 643314197. The reversal of 643314194 is 491413346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 351075169 + 292239025 = 18737^2 + 17095^2 .

It is not an unprimeable number, because it can be changed into a prime (643314197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160828547 + ... + 160828550.

Almost surely, 2^643314194 is an apocalyptic number.

643314194 is a deficient number, since it is larger than the sum of its proper divisors (321657100).

643314194 is a wasteful number, since it uses less digits than its factorization.

643314194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321657099.

The product of its digits is 31104, while the sum is 35.

The square root of 643314194 is about 25363.6392104919. The cubic root of 643314194 is about 863.2588603523.

The spelling of 643314194 in words is "six hundred forty-three million, three hundred fourteen thousand, one hundred ninety-four".