858521218 has 4 divisors (see below), whose sum is σ = 1287781830. Its totient is φ = 429260608.

The previous prime is 858521197. The next prime is 858521239. The reversal of 858521218 is 812125858.

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

It is an interprime number because it is at equal distance from previous prime (858521197) and next prime (858521239).

It can be written as a sum of positive squares in only one way, i.e., 807298569 + 51222649 = 28413^2 + 7157^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214630303 + ... + 214630306.

Almost surely, 2^858521218 is an apocalyptic number.

858521218 is a deficient number, since it is larger than the sum of its proper divisors (429260612).

858521218 is a wasteful number, since it uses less digits than its factorization.

858521218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429260611.

The product of its digits is 51200, while the sum is 40.

The square root of 858521218 is about 29300.5327255325. The cubic root of 858521218 is about 950.4231606977.

The spelling of 858521218 in words is "eight hundred fifty-eight million, five hundred twenty-one thousand, two hundred eighteen".