166001643 has 20 divisors (see below), whose sum is σ = 250774920. Its totient is φ = 109419552.

The previous prime is 166001639. The next prime is 166001653. The reversal of 166001643 is 346100661.

166001643 is a `hidden beast` number, since 1 + 6 + 600 + 16 + 43 = 666.

It is not a de Polignac number, because 166001643 - 2² = 166001639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (166001623) 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 19 ways as a sum of consecutive naturals, for example, 4305 + ... + 18722.

It is an arithmetic number, because the mean of its divisors is an integer number (12538746).

Almost surely, 2^166001643 is an apocalyptic number.

166001643 is a deficient number, since it is larger than the sum of its proper divisors (84773277).

166001643 is an equidigital number, since it uses as much as digits as its factorization.

166001643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23128 (or 23119 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 166001643 is about 12884.1624873330. The cubic root of 166001643 is about 549.5882791974.

The spelling of 166001643 in words is "one hundred sixty-six million, one thousand, six hundred forty-three".