166681451 has 8 divisors (see below), whose sum is σ = 172262784. Its totient is φ = 161112960.

The previous prime is 166681409. The next prime is 166681457. The reversal of 166681451 is 154186661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166681451 is a prime.

It is a super-2 number, since 2×166681451² = 55565412214930802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166681457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28211 + ... + 33603.

It is an arithmetic number, because the mean of its divisors is an integer number (21532848).

Almost surely, 2^166681451 is an apocalyptic number.

166681451 is a deficient number, since it is larger than the sum of its proper divisors (5581333).

166681451 is an equidigital number, since it uses as much as digits as its factorization.

166681451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6421.

The product of its digits is 34560, while the sum is 38.

The square root of 166681451 is about 12910.5170694283. The cubic root of 166681451 is about 550.3374799323.

The spelling of 166681451 in words is "one hundred sixty-six million, six hundred eighty-one thousand, four hundred fifty-one".