166640 has 20 divisors (see below), whose sum is σ = 387624. Its totient is φ = 66624.

The previous prime is 166631. The next prime is 166643. The reversal of 166640 is 46661.

166640 = T₄ + T₅ + ... + T₉₉.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-4 number, since 4×166640⁴ (a number of 22 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166643) 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, 962 + ... + 1121.

2¹⁶⁶⁶⁴⁰ is an apocalyptic number.

166640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166640 is an abundant number, since it is smaller than the sum of its proper divisors (220984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166640 is a wasteful number, since it uses less digits than its factorization.

166640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 166640 is about 408.2156292941. The cubic root of 166640 is about 55.0291856119.

The spelling of 166640 in words is "one hundred sixty-six thousand, six hundred forty".