15661666067 has 4 divisors (see below), whose sum is σ = 15662505696. Its totient is φ = 15660826440.

The previous prime is 15661666057. The next prime is 15661666087. The reversal of 15661666067 is 76066616651.

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 15661666067 - 2¹⁶ = 15661600531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661666037) 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, 391184 + ... + 429357.

It is an arithmetic number, because the mean of its divisors is an integer number (3915626424).

Almost surely, 2^15661666067 is an apocalyptic number.

15661666067 is a deficient number, since it is larger than the sum of its proper divisors (839629).

15661666067 is an equidigital number, since it uses as much as digits as its factorization.

15661666067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839628.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The spelling of 15661666067 in words is "fifteen billion, six hundred sixty-one million, six hundred sixty-six thousand, sixty-seven".