1818651820 has 12 divisors (see below), whose sum is σ = 3819168864. Its totient is φ = 727460720.

The previous prime is 1818651817. The next prime is 1818651827. The reversal of 1818651820 is 281568181.

It is not an unprimeable number, because it can be changed into a prime (1818651827) 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, 45466276 + ... + 45466315.

It is an arithmetic number, because the mean of its divisors is an integer number (318264072).

Almost surely, 2^1818651820 is an apocalyptic number.

1818651820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1818651820 is an abundant number, since it is smaller than the sum of its proper divisors (2000517044).

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

1818651820 is a wasteful number, since it uses less digits than its factorization.

1818651820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90932600 (or 90932598 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 40.

The square root of 1818651820 is about 42645.6541748394. The cubic root of 1818651820 is about 1220.6276041670.

The spelling of 1818651820 in words is "one billion, eight hundred eighteen million, six hundred fifty-one thousand, eight hundred twenty".