1818666520 has 128 divisors (see below), whose sum is σ = 4638876480. Its totient is φ = 635904000.

The previous prime is 1818666517. The next prime is 1818666523. The reversal of 1818666520 is 256668181.

It is an interprime number because it is at equal distance from previous prime (1818666517) and next prime (1818666523).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818666523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1316230 + ... + 1317610.

Almost surely, 2^1818666520 is an apocalyptic number.

1818666520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1818666520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2319438240).

1818666520 is an abundant number, since it is smaller than the sum of its proper divisors (2820209960).

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

1818666520 is a wasteful number, since it uses less digits than its factorization.

1818666520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1517 (or 1513 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 1818666520 is about 42645.8265249954. The cubic root of 1818666520 is about 1220.6308928994.

The spelling of 1818666520 in words is "one billion, eight hundred eighteen million, six hundred sixty-six thousand, five hundred twenty".