166721946 has 8 divisors (see below), whose sum is σ = 333443904. Its totient is φ = 55573980.

The previous prime is 166721939. The next prime is 166721953. The reversal of 166721946 is 649127661.

It is an interprime number because it is at equal distance from previous prime (166721939) and next prime (166721953).

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

166721946 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 166721898 and 166721907.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13893490 + ... + 13893501.

It is an arithmetic number, because the mean of its divisors is an integer number (41680488).

Almost surely, 2^166721946 is an apocalyptic number.

166721946 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

166721946 is a wasteful number, since it uses less digits than its factorization.

166721946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27786996.

The product of its digits is 108864, while the sum is 42.

The square root of 166721946 is about 12912.0852692352. The cubic root of 166721946 is about 550.3820442027.

The spelling of 166721946 in words is "one hundred sixty-six million, seven hundred twenty-one thousand, nine hundred forty-six".