1818211815387 has 24 divisors (see below), whose sum is σ = 2891346023280. Its totient is φ = 1091836946880.

The previous prime is 1818211815313. The next prime is 1818211815419. The reversal of 1818211815387 is 7835181128181.

1818211815387 is a `hidden beast` number, since 1 + 8 + 1 + 8 + 21 + 1 + 81 + 538 + 7 = 666.

It is not a de Polignac number, because 1818211815387 - 2¹¹ = 1818211813339 is a prime.

It is a super-2 number, since 2×1818211815387² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1818211815187) 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, 84235888 + ... + 84257469.

It is an arithmetic number, because the mean of its divisors is an integer number (120472750970).

Almost surely, 2^{1818211815387} is an apocalyptic number.

1818211815387 is a deficient number, since it is larger than the sum of its proper divisors (1073134207893).

1818211815387 is a wasteful number, since it uses less digits than its factorization.

1818211815387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168493483 (or 168493480 counting only the distinct ones).

The product of its digits is 860160, while the sum is 54.

The spelling of 1818211815387 in words is "one trillion, eight hundred eighteen billion, two hundred eleven million, eight hundred fifteen thousand, three hundred eighty-seven".