166731 has 8 divisors (see below), whose sum is σ = 224400. Its totient is φ = 110112.

The previous prime is 166723. The next prime is 166739. The reversal of 166731 is 137661.

166731 is digitally balanced in base 2 and base 7, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (166723) and next prime (166739).

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

It is not a de Polignac number, because 166731 - 2³ = 166723 is a prime.

It is a super-2 number, since 2×166731² = 55598452722, which contains 22 as substring.

166731 is strictly pandigital in base 7.

166731 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (166739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261 + ... + 633.

It is an arithmetic number, because the mean of its divisors is an integer number (28050).

2¹⁶⁶⁷³¹ is an apocalyptic number.

166731 is a deficient number, since it is larger than the sum of its proper divisors (57669).

166731 is a wasteful number, since it uses less digits than its factorization.

166731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525.

The product of its digits is 756, while the sum is 24.

The square root of 166731 is about 408.3270747820. The cubic root of 166731 is about 55.0392007036.

The spelling of 166731 in words is "one hundred sixty-six thousand, seven hundred thirty-one".