1945398218 has 4 divisors (see below), whose sum is σ = 2918097330. Its totient is φ = 972699108.

The previous prime is 1945398199. The next prime is 1945398229. The reversal of 1945398218 is 8128935491.

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., 1820472889 + 124925329 = 42667^2 + 11177^2 .

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 as a sum of consecutive naturals, namely, 486349553 + ... + 486349556.

Almost surely, 2^1945398218 is an apocalyptic number.

1945398218 is a deficient number, since it is larger than the sum of its proper divisors (972699112).

1945398218 is an equidigital number, since it uses as much as digits as its factorization.

1945398218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972699111.

The product of its digits is 622080, while the sum is 50.

The square root of 1945398218 is about 44106.6686341193. The cubic root of 1945398218 is about 1248.3494413241.

The spelling of 1945398218 in words is "one billion, nine hundred forty-five million, three hundred ninety-eight thousand, two hundred eighteen".