16115561243 has 4 divisors (see below), whose sum is σ = 16118790000. Its totient is φ = 16112332488.

The previous prime is 16115561239. The next prime is 16115561257. The reversal of 16115561243 is 34216551161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16115561243 - 2² = 16115561239 is a prime.

It is a super-2 number, since 2×16115561243² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16115561743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1606880 + ... + 1616877.

It is an arithmetic number, because the mean of its divisors is an integer number (4029697500).

Almost surely, 2^16115561243 is an apocalyptic number.

16115561243 is a deficient number, since it is larger than the sum of its proper divisors (3228757).

16115561243 is an equidigital number, since it uses as much as digits as its factorization.

16115561243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3228756.

The product of its digits is 21600, while the sum is 35.

The spelling of 16115561243 in words is "sixteen billion, one hundred fifteen million, five hundred sixty-one thousand, two hundred forty-three".