166143947 has 4 divisors (see below), whose sum is σ = 166623096. Its totient is φ = 165664800.

The previous prime is 166143937. The next prime is 166143953. The reversal of 166143947 is 749341661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 166143947 - 2⁶ = 166143883 is a prime.

It is a super-2 number, since 2×166143947² = 55207622249477618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166143917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239054 + ... + 239747.

It is an arithmetic number, because the mean of its divisors is an integer number (41655774).

Almost surely, 2^166143947 is an apocalyptic number.

166143947 is a deficient number, since it is larger than the sum of its proper divisors (479149).

166143947 is an equidigital number, since it uses as much as digits as its factorization.

166143947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479148.

The product of its digits is 108864, while the sum is 41.

The square root of 166143947 is about 12889.6837432111. The cubic root of 166143947 is about 549.7452781920.

The spelling of 166143947 in words is "one hundred sixty-six million, one hundred forty-three thousand, nine hundred forty-seven".