166897891 has 16 divisors (see below), whose sum is σ = 180658080. Its totient is φ = 153607680.

The previous prime is 166897889. The next prime is 166897897. The reversal of 166897891 is 198798661.

It is a cyclic number.

It is not a de Polignac number, because 166897891 - 2¹ = 166897889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166897897) 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, 235045 + ... + 235753.

It is an arithmetic number, because the mean of its divisors is an integer number (11291130).

Almost surely, 2^166897891 is an apocalyptic number.

166897891 is a deficient number, since it is larger than the sum of its proper divisors (13760189).

166897891 is a wasteful number, since it uses less digits than its factorization.

166897891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014.

The product of its digits is 1306368, while the sum is 55.

The square root of 166897891 is about 12918.8966634152. The cubic root of 166897891 is about 550.5755858577.

The spelling of 166897891 in words is "one hundred sixty-six million, eight hundred ninety-seven thousand, eight hundred ninety-one".