16661326415 has 8 divisors (see below), whose sum is σ = 20481240528. Its totient is φ = 13003961920.

The previous prime is 16661326411. The next prime is 16661326421. The reversal of 16661326415 is 51462316661.

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

It is not a de Polignac number, because 16661326415 - 2² = 16661326411 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661326411) 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, 40637177 + ... + 40637586.

It is an arithmetic number, because the mean of its divisors is an integer number (2560155066).

Almost surely, 2^16661326415 is an apocalyptic number.

16661326415 is a deficient number, since it is larger than the sum of its proper divisors (3819914113).

16661326415 is an equidigital number, since it uses as much as digits as its factorization.

16661326415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81274809.

The product of its digits is 155520, while the sum is 41.

The spelling of 16661326415 in words is "sixteen billion, six hundred sixty-one million, three hundred twenty-six thousand, four hundred fifteen".