8181620 has 12 divisors (see below), whose sum is σ = 17181444. Its totient is φ = 3272640.

The previous prime is 8181617. The next prime is 8181623. The reversal of 8181620 is 261818.

It is an interprime number because it is at equal distance from previous prime (8181617) and next prime (8181623).

It can be written as a sum of positive squares in 2 ways, for example, as 2630884 + 5550736 = 1622^2 + 2356^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 8181620.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8181623) 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, 204521 + ... + 204560.

It is an arithmetic number, because the mean of its divisors is an integer number (1431787).

Almost surely, 2^8181620 is an apocalyptic number.

It is an amenable number.

8181620 is an abundant number, since it is smaller than the sum of its proper divisors (8999824).

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

8181620 is a wasteful number, since it uses less digits than its factorization.

8181620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409090 (or 409088 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 8181620 is about 2860.3531250529. The cubic root of 8181620 is about 201.5021888943.

The spelling of 8181620 in words is "eight million, one hundred eighty-one thousand, six hundred twenty".