166451 has 4 divisors (see below), whose sum is σ = 173712. Its totient is φ = 159192.

The previous prime is 166429. The next prime is 166457. The reversal of 166451 is 154661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 154661 = 13 ⋅11897.

It is a cyclic number.

It is not a de Polignac number, because 166451 - 2¹⁴ = 150067 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 7237 = 166451 / (1 + 6 + 6 + 4 + 5 + 1).

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (166457) 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, 3596 + ... + 3641.

It is an arithmetic number, because the mean of its divisors is an integer number (43428).

2¹⁶⁶⁴⁵¹ is an apocalyptic number.

166451 is a deficient number, since it is larger than the sum of its proper divisors (7261).

166451 is an equidigital number, since it uses as much as digits as its factorization.

166451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7260.

The product of its digits is 720, while the sum is 23.

The square root of 166451 is about 407.9840683164. The cubic root of 166451 is about 55.0083733808.

The spelling of 166451 in words is "one hundred sixty-six thousand, four hundred fifty-one".