685229218 has 4 divisors (see below), whose sum is σ = 1027843830. Its totient is φ = 342614608.

The previous prime is 685229213. The next prime is 685229231. The reversal of 685229218 is 812922586.

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., 599907049 + 85322169 = 24493^2 + 9237^2 .

It is not an unprimeable number, because it can be changed into a prime (685229213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171307303 + ... + 171307306.

Almost surely, 2^685229218 is an apocalyptic number.

685229218 is a deficient number, since it is larger than the sum of its proper divisors (342614612).

685229218 is a wasteful number, since it uses less digits than its factorization.

685229218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342614611.

The product of its digits is 138240, while the sum is 43.

The square root of 685229218 is about 26176.8832751342. The cubic root of 685229218 is about 881.6142966921.

The spelling of 685229218 in words is "six hundred eighty-five million, two hundred twenty-nine thousand, two hundred eighteen".