7138181 has 4 divisors (see below), whose sum is σ = 7558092. Its totient is φ = 6718272.

The previous prime is 7138177. The next prime is 7138193. The reversal of 7138181 is 1818317.

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 5152900 + 1985281 = 2270^2 + 1409^2 .

It is a cyclic number.

It is not a de Polignac number, because 7138181 - 2² = 7138177 is a prime.

It is a super-2 number, since 2×7138181² = 101907255977522, 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 (7138121) 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 3 ways as a sum of consecutive naturals, for example, 209930 + ... + 209963.

It is an arithmetic number, because the mean of its divisors is an integer number (1889523).

Almost surely, 2^7138181 is an apocalyptic number.

It is an amenable number.

7138181 is a deficient number, since it is larger than the sum of its proper divisors (419911).

7138181 is a wasteful number, since it uses less digits than its factorization.

7138181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419910.

The product of its digits is 1344, while the sum is 29.

The square root of 7138181 is about 2671.7374496758. The cubic root of 7138181 is about 192.5436433344.

The spelling of 7138181 in words is "seven million, one hundred thirty-eight thousand, one hundred eighty-one".