166385398399 has 16 divisors (see below), whose sum is σ = 187954992000. Its totient is φ = 145900004320.

The previous prime is 166385398381. The next prime is 166385398423. The reversal of 166385398399 is 993893583661.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 166385398399 - 2⁹ = 166385397887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166385398339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69132 + ... + 580990.

It is an arithmetic number, because the mean of its divisors is an integer number (11747187000).

Almost surely, 2^166385398399 is an apocalyptic number.

166385398399 is a deficient number, since it is larger than the sum of its proper divisors (21569593601).

166385398399 is a wasteful number, since it uses less digits than its factorization.

166385398399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512918.

The product of its digits is 226748160, while the sum is 70.

The spelling of 166385398399 in words is "one hundred sixty-six billion, three hundred eighty-five million, three hundred ninety-eight thousand, three hundred ninety-nine".