7228181 has 4 divisors (see below), whose sum is σ = 7235052. Its totient is φ = 7221312.

The previous prime is 7228153. The next prime is 7228183. The reversal of 7228181 is 1818227.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4165681 + 3062500 = 2041^2 + 1750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7228181 is a prime.

It is a super-2 number, since 2×7228181² = 104493201137522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7228183) 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, 1490 + ... + 4083.

It is an arithmetic number, because the mean of its divisors is an integer number (1808763).

Almost surely, 2^7228181 is an apocalyptic number.

It is an amenable number.

7228181 is a deficient number, since it is larger than the sum of its proper divisors (6871).

7228181 is a wasteful number, since it uses less digits than its factorization.

7228181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6870.

The product of its digits is 1792, while the sum is 29.

The square root of 7228181 is about 2688.5276639826. The cubic root of 7228181 is about 193.3494790981.

The spelling of 7228181 in words is "seven million, two hundred twenty-eight thousand, one hundred eighty-one".