7218861 has 8 divisors (see below), whose sum is σ = 10365600. Its totient is φ = 4442352.

The previous prime is 7218859. The next prime is 7218889. The reversal of 7218861 is 1688127.

It is a happy number.

7218861 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7218861 - 2¹ = 7218859 is a prime.

It is a super-2 number, since 2×7218861² = 104223908274642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7218821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92511 + ... + 92588.

It is an arithmetic number, because the mean of its divisors is an integer number (1295700).

Almost surely, 2^7218861 is an apocalyptic number.

It is an amenable number.

7218861 is a deficient number, since it is larger than the sum of its proper divisors (3146739).

7218861 is a wasteful number, since it uses less digits than its factorization.

7218861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185115.

The product of its digits is 5376, while the sum is 33.

The square root of 7218861 is about 2686.7938141956. The cubic root of 7218861 is about 193.2663418973.

The spelling of 7218861 in words is "seven million, two hundred eighteen thousand, eight hundred sixty-one".