16661111551 has 8 divisors (see below), whose sum is σ = 19042089120. Its totient is φ = 14280338688.

The previous prime is 16661111531. The next prime is 16661111567. The reversal of 16661111551 is 15511116661.

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

It is not a de Polignac number, because 16661111551 - 2³¹ = 14513627903 is a prime.

It is a super-2 number, since 2×16661111551² (a number of 21 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 (16661111531) 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 7 ways as a sum of consecutive naturals, for example, 216795 + ... + 283411.

It is an arithmetic number, because the mean of its divisors is an integer number (2380261140).

Almost surely, 2^16661111551 is an apocalyptic number.

16661111551 is a deficient number, since it is larger than the sum of its proper divisors (2380977569).

16661111551 is an equidigital number, since it uses as much as digits as its factorization.

16661111551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102353.

The product of its digits is 5400, while the sum is 34.

The spelling of 16661111551 in words is "sixteen billion, six hundred sixty-one million, one hundred eleven thousand, five hundred fifty-one".