218181631541 has 4 divisors (see below), whose sum is σ = 218189524800. Its totient is φ = 218173738284.

The previous prime is 218181631519. The next prime is 218181631553. The reversal of 218181631541 is 145136181812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218181631541 - 2¹⁸ = 218181369397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218181631741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3905021 + ... + 3960498.

It is an arithmetic number, because the mean of its divisors is an integer number (54547381200).

Almost surely, 2^218181631541 is an apocalyptic number.

It is an amenable number.

218181631541 is a deficient number, since it is larger than the sum of its proper divisors (7893259).

218181631541 is an equidigital number, since it uses as much as digits as its factorization.

218181631541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7893258.

The product of its digits is 46080, while the sum is 41.

The spelling of 218181631541 in words is "two hundred eighteen billion, one hundred eighty-one million, six hundred thirty-one thousand, five hundred forty-one".