166205640 has 64 divisors (see below), whose sum is σ = 499478400. Its totient is φ = 44244992.

The previous prime is 166205623. The next prime is 166205647. The reversal of 166205640 is 46502661.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 166205598 and 166205607.

It is not an unprimeable number, because it can be changed into a prime (166205647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117256 + ... + 118664.

It is an arithmetic number, because the mean of its divisors is an integer number (7804350).

Almost surely, 2^166205640 is an apocalyptic number.

166205640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166205640 is an abundant number, since it is smaller than the sum of its proper divisors (333272760).

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

166205640 is a wasteful number, since it uses less digits than its factorization.

166205640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2406 (or 2402 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 166205640 is about 12892.0766364461. The cubic root of 166205640 is about 549.8133140510.

The spelling of 166205640 in words is "one hundred sixty-six million, two hundred five thousand, six hundred forty".