166643942399 has 16 divisors (see below), whose sum is σ = 193167348480. Its totient is φ = 142079180160.

The previous prime is 166643942369. The next prime is 166643942401. The reversal of 166643942399 is 993249346661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166643942399 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 (166643942329) 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, 1521539 + ... + 1627380.

It is an arithmetic number, because the mean of its divisors is an integer number (12072959280).

Almost surely, 2^166643942399 is an apocalyptic number.

166643942399 is a deficient number, since it is larger than the sum of its proper divisors (26523406081).

166643942399 is a wasteful number, since it uses less digits than its factorization.

166643942399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3149230.

The product of its digits is 45349632, while the sum is 62.

The spelling of 166643942399 in words is "one hundred sixty-six billion, six hundred forty-three million, nine hundred forty-two thousand, three hundred ninety-nine".