642746232218 has 4 divisors (see below), whose sum is σ = 964119348330. Its totient is φ = 321373116108.

The previous prime is 642746232187. The next prime is 642746232229. The reversal of 642746232218 is 812232647246.

642746232218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 812232647246 = 2 ⋅406116323623.

It can be written as a sum of positive squares in only one way, i.e., 370494994489 + 272251237729 = 608683^2 + 521777^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160686558053 + ... + 160686558056.

Almost surely, 2^642746232218 is an apocalyptic number.

642746232218 is a deficient number, since it is larger than the sum of its proper divisors (321373116112).

642746232218 is a wasteful number, since it uses less digits than its factorization.

642746232218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321373116111.

The product of its digits is 1548288, while the sum is 47.

The spelling of 642746232218 in words is "six hundred forty-two billion, seven hundred forty-six million, two hundred thirty-two thousand, two hundred eighteen".