7181820 has 72 divisors (see below), whose sum is σ = 23076144. Its totient is φ = 1801728.

The previous prime is 7181761. The next prime is 7181827. The reversal of 7181820 is 281817.

It is a super-3 number, since 3×7181820³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7181827) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1887 + ... + 4233.

It is an arithmetic number, because the mean of its divisors is an integer number (320502).

Almost surely, 2^7181820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7181820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11538072).

7181820 is an abundant number, since it is smaller than the sum of its proper divisors (15894324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7181820 is a wasteful number, since it uses less digits than its factorization.

7181820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379 (or 2374 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 7181820 is about 2679.8917888601. The cubic root of 7181820 is about 192.9352158914.

It can be divided in two parts, 7181 and 820, that added together give a triangular number (8001 = T₁₂₆).

The spelling of 7181820 in words is "seven million, one hundred eighty-one thousand, eight hundred twenty".