161511666615543 has 8 divisors (see below), whose sum is σ = 226683040864000. Its totient is φ = 102007368388728.

The previous prime is 161511666615491. The next prime is 161511666615569. The reversal of 161511666615543 is 345516666115161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161511666615543 - 2⁶ = 161511666615479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 2833538010799 = 161511666615543 / (1 + 6 + 1 + 5 + 1 + 1 + 6 + 6 + 6 + 6 + 1 + 5 + 5 + 4 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161511666615743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1416769005343 + ... + 1416769005456.

It is an arithmetic number, because the mean of its divisors is an integer number (28335380108000).

Almost surely, 2^{161511666615543} is an apocalyptic number.

161511666615543 is a deficient number, since it is larger than the sum of its proper divisors (65171374248457).

161511666615543 is a wasteful number, since it uses less digits than its factorization.

161511666615543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2833538010821.

The product of its digits is 11664000, while the sum is 57.

The spelling of 161511666615543 in words is "one hundred sixty-one trillion, five hundred eleven billion, six hundred sixty-six million, six hundred fifteen thousand, five hundred forty-three".