166810491 has 6 divisors (see below), whose sum is σ = 240948500. Its totient is φ = 111206988.

The previous prime is 166810403. The next prime is 166810499. The reversal of 166810491 is 194018661.

It is a happy number.

166810491 is a `hidden beast` number, since 166 + 8 + 1 + 0 + 491 = 666.

It is not a de Polignac number, because 166810491 - 2¹⁴ = 166794107 is a prime.

It is a super-2 number, since 2×166810491² = 55651479815322162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166810499) 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 5 ways as a sum of consecutive naturals, for example, 9267241 + ... + 9267258.

Almost surely, 2^166810491 is an apocalyptic number.

166810491 is a deficient number, since it is larger than the sum of its proper divisors (74138009).

166810491 is a wasteful number, since it uses less digits than its factorization.

166810491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18534505 (or 18534502 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 166810491 is about 12915.5135786387. The cubic root of 166810491 is about 550.4794617981.

The spelling of 166810491 in words is "one hundred sixty-six million, eight hundred ten thousand, four hundred ninety-one".