1818211836 has 72 divisors (see below), whose sum is σ = 4968507600. Its totient is φ = 515977728.

The previous prime is 1818211831. The next prime is 1818211841. The reversal of 1818211836 is 6381128181.

It is an interprime number because it is at equal distance from previous prime (1818211831) and next prime (1818211841).

It is a junction number, because it is equal to n+sod(n) for n = 1818211794 and 1818211803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818211831) 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, 77236 + ... + 97988.

It is an arithmetic number, because the mean of its divisors is an integer number (69007050).

Almost surely, 2^1818211836 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 1818211836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2484253800).

1818211836 is an abundant number, since it is smaller than the sum of its proper divisors (3150295764).

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

1818211836 is a wasteful number, since it uses less digits than its factorization.

1818211836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20923 (or 20914 counting only the distinct ones).

The product of its digits is 18432, while the sum is 39.

The square root of 1818211836 is about 42640.4952597880. The cubic root of 1818211836 is about 1220.5291612938.

The spelling of 1818211836 in words is "one billion, eight hundred eighteen million, two hundred eleven thousand, eight hundred thirty-six".