166865820 has 48 divisors (see below), whose sum is σ = 509701248. Its totient is φ = 40452160.

The previous prime is 166865807. The next prime is 166865821. The reversal of 166865820 is 28568661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166865821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125754 + ... + 127073.

It is an arithmetic number, because the mean of its divisors is an integer number (10618776).

Almost surely, 2^166865820 is an apocalyptic number.

166865820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166865820 is an abundant number, since it is smaller than the sum of its proper divisors (342835428).

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

166865820 is a wasteful number, since it uses less digits than its factorization.

166865820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252850 (or 252848 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 166865820 is about 12917.6553600102. The cubic root of 166865820 is about 550.5403175056.

The spelling of 166865820 in words is "one hundred sixty-six million, eight hundred sixty-five thousand, eight hundred twenty".