186866815381 has 16 divisors (see below), whose sum is σ = 205134249600. Its totient is φ = 169653550528.

The previous prime is 186866815379. The next prime is 186866815391. The reversal of 186866815381 is 183518668681.

It is not a de Polignac number, because 186866815381 - 2¹ = 186866815379 is a prime.

It is a super-2 number, since 2×186866815381² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (186866815351) 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, 2334886 + ... + 2413591.

It is an arithmetic number, because the mean of its divisors is an integer number (12820890600).

Almost surely, 2^186866815381 is an apocalyptic number.

It is an amenable number.

186866815381 is a deficient number, since it is larger than the sum of its proper divisors (18267434219).

186866815381 is a wasteful number, since it uses less digits than its factorization.

186866815381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4748588.

The product of its digits is 13271040, while the sum is 61.

The spelling of 186866815381 in words is "one hundred eighty-six billion, eight hundred sixty-six million, eight hundred fifteen thousand, three hundred eighty-one".