1811856380487 has 16 divisors (see below), whose sum is σ = 2521225835520. Its totient is φ = 1155211513632.

The previous prime is 1811856380473. The next prime is 1811856380491. The reversal of 1811856380487 is 7840836581181.

It is not a de Polignac number, because 1811856380487 - 2⁶ = 1811856380423 is a prime.

It is a super-2 number, since 2×1811856380487² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1811856380487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811856380287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1531312 + ... + 2443077.

It is an arithmetic number, because the mean of its divisors is an integer number (157576614720).

Almost surely, 2^{1811856380487} is an apocalyptic number.

1811856380487 is a deficient number, since it is larger than the sum of its proper divisors (709369455033).

1811856380487 is a wasteful number, since it uses less digits than its factorization.

1811856380487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3981022.

The product of its (nonzero) digits is 10321920, while the sum is 60.

The spelling of 1811856380487 in words is "one trillion, eight hundred eleven billion, eight hundred fifty-six million, three hundred eighty thousand, four hundred eighty-seven".