8218121 has 4 divisors (see below), whose sum is σ = 8330772. Its totient is φ = 8105472.

The previous prime is 8218109. The next prime is 8218139. The reversal of 8218121 is 1218128.

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 2 ways, for example, as 5017600 + 3200521 = 2240^2 + 1789^2 .

It is a cyclic number.

It is not a de Polignac number, because 8218121 - 2⁶ = 8218057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8218141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56216 + ... + 56361.

It is an arithmetic number, because the mean of its divisors is an integer number (2082693).

Almost surely, 2^8218121 is an apocalyptic number.

It is an amenable number.

8218121 is a deficient number, since it is larger than the sum of its proper divisors (112651).

8218121 is a wasteful number, since it uses less digits than its factorization.

8218121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112650.

The product of its digits is 256, while the sum is 23.

The square root of 8218121 is about 2866.7265303827. The cubic root of 8218121 is about 201.8014010576.

The spelling of 8218121 in words is "eight million, two hundred eighteen thousand, one hundred twenty-one".