166564947 has 4 divisors (see below), whose sum is σ = 222086600. Its totient is φ = 111043296.

The previous prime is 166564927. The next prime is 166564949. The reversal of 166564947 is 749465661.

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

It is not a de Polignac number, because 166564947 - 2⁶ = 166564883 is a prime.

It is a super-2 number, since 2×166564947² = 55487763138225618, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166564896 and 166564905.

It is not an unprimeable number, because it can be changed into a prime (166564949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27760822 + ... + 27760827.

It is an arithmetic number, because the mean of its divisors is an integer number (55521650).

Almost surely, 2^166564947 is an apocalyptic number.

166564947 is a deficient number, since it is larger than the sum of its proper divisors (55521653).

166564947 is an equidigital number, since it uses as much as digits as its factorization.

166564947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55521652.

The product of its digits is 1088640, while the sum is 48.

The square root of 166564947 is about 12906.0043003247. The cubic root of 166564947 is about 550.2092283852.

The spelling of 166564947 in words is "one hundred sixty-six million, five hundred sixty-four thousand, nine hundred forty-seven".