8157218 has 4 divisors (see below), whose sum is σ = 12235830. Its totient is φ = 4078608.

The previous prime is 8157211. The next prime is 8157221. The reversal of 8157218 is 8127518.

It is a happy number.

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., 5555449 + 2601769 = 2357^2 + 1613^2 .

It is not an unprimeable number, because it can be changed into a prime (8157211) 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, 2039303 + ... + 2039306.

Almost surely, 2^8157218 is an apocalyptic number.

8157218 is a deficient number, since it is larger than the sum of its proper divisors (4078612).

8157218 is a wasteful number, since it uses less digits than its factorization.

8157218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4078611.

The product of its digits is 4480, while the sum is 32.

The square root of 8157218 is about 2856.0843825069. The cubic root of 8157218 is about 201.3016600273.

The spelling of 8157218 in words is "eight million, one hundred fifty-seven thousand, two hundred eighteen".