166605406 has 32 divisors (see below), whose sum is σ = 298637280. Its totient is φ = 68812800.

The previous prime is 166605403. The next prime is 166605409. The reversal of 166605406 is 604506661.

It is an interprime number because it is at equal distance from previous prime (166605403) and next prime (166605409).

It is a super-2 number, since 2×166605406² = 55514722616849672, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166605403) 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, 3166 + ... + 18526.

It is an arithmetic number, because the mean of its divisors is an integer number (9332415).

Almost surely, 2^166605406 is an apocalyptic number.

166605406 is a deficient number, since it is larger than the sum of its proper divisors (132031874).

166605406 is a wasteful number, since it uses less digits than its factorization.

166605406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15420.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 166605406 is about 12907.5716538782. The cubic root of 166605406 is about 550.2537737981.

The spelling of 166605406 in words is "one hundred sixty-six million, six hundred five thousand, four hundred six".