18871812 has 48 divisors (see below), whose sum is σ = 49230720. Its totient is φ = 6251616.

The previous prime is 18871789. The next prime is 18871841. The reversal of 18871812 is 21817881.

It is a super-2 number, since 2×18871812² = 712290576326688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20833 + ... + 21719.

It is an arithmetic number, because the mean of its divisors is an integer number (1025640).

Almost surely, 2^18871812 is an apocalyptic number.

18871812 is a gapful number since it is divisible by the number (12) 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 18871812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24615360).

18871812 is an abundant number, since it is smaller than the sum of its proper divisors (30358908).

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

18871812 is a wasteful number, since it uses less digits than its factorization.

18871812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097 (or 1089 counting only the distinct ones).

The product of its digits is 7168, while the sum is 36.

The square root of 18871812 is about 4344.1698861808. The cubic root of 18871812 is about 266.2387100946.

It can be divided in two parts, 18871 and 812, that added together give a 9-th power (19683 = 3⁹).

The spelling of 18871812 in words is "eighteen million, eight hundred seventy-one thousand, eight hundred twelve".