166186993 has 16 divisors (see below), whose sum is σ = 193019904. Its totient is φ = 140147280.

The previous prime is 166186991. The next prime is 166187027. The reversal of 166186993 is 399681661.

It is not a de Polignac number, because 166186993 - 2¹ = 166186991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166186991) 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 15 ways as a sum of consecutive naturals, for example, 115746 + ... + 117172.

It is an arithmetic number, because the mean of its divisors is an integer number (12063744).

Almost surely, 2^166186993 is an apocalyptic number.

It is an amenable number.

166186993 is a deficient number, since it is larger than the sum of its proper divisors (26832911).

166186993 is a wasteful number, since it uses less digits than its factorization.

166186993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1692.

The product of its digits is 419904, while the sum is 49.

The square root of 166186993 is about 12891.3534200254. The cubic root of 166186993 is about 549.7927516676.

The spelling of 166186993 in words is "one hundred sixty-six million, one hundred eighty-six thousand, nine hundred ninety-three".