7218689 has 4 divisors (see below), whose sum is σ = 7598640. Its totient is φ = 6838740.

The previous prime is 7218677. The next prime is 7218697. The reversal of 7218689 is 9868127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7218689 - 2⁸ = 7218433 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7218649) 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, 189947 + ... + 189984.

It is an arithmetic number, because the mean of its divisors is an integer number (1899660).

Almost surely, 2^7218689 is an apocalyptic number.

It is an amenable number.

7218689 is a deficient number, since it is larger than the sum of its proper divisors (379951).

7218689 is a wasteful number, since it uses less digits than its factorization.

7218689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379950.

The product of its digits is 48384, while the sum is 41.

The square root of 7218689 is about 2686.7618055942. The cubic root of 7218689 is about 193.2648069333.

The spelling of 7218689 in words is "seven million, two hundred eighteen thousand, six hundred eighty-nine".