166691479 has 4 divisors (see below), whose sum is σ = 166735360. Its totient is φ = 166647600.

The previous prime is 166691431. The next prime is 166691531. The reversal of 166691479 is 974196661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 974196661 = 18313 ⋅53197.

It is a cyclic number.

It is not a de Polignac number, because 166691479 - 2¹⁹ = 166167191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166691279) 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, 15639 + ... + 24040.

It is an arithmetic number, because the mean of its divisors is an integer number (41683840).

Almost surely, 2^166691479 is an apocalyptic number.

166691479 is a deficient number, since it is larger than the sum of its proper divisors (43881).

166691479 is an equidigital number, since it uses as much as digits as its factorization.

166691479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43880.

The product of its digits is 489888, while the sum is 49.

The square root of 166691479 is about 12910.9054291324. The cubic root of 166691479 is about 550.3485163005.

The spelling of 166691479 in words is "one hundred sixty-six million, six hundred ninety-one thousand, four hundred seventy-nine".