166067021 has 6 divisors (see below), whose sum is σ = 171865290. Its totient is φ = 160273568.

The previous prime is 166066991. The next prime is 166067023. The reversal of 166067021 is 120760661.

It can be written as a sum of positive squares in 3 ways, for example, as 9066121 + 157000900 = 3011^2 + 12530^2 .

It is not a de Polignac number, because 166067021 - 2²² = 161872717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166067023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 68201 + ... + 70593.

It is an arithmetic number, because the mean of its divisors is an integer number (28644215).

Almost surely, 2^166067021 is an apocalyptic number.

It is an amenable number.

166067021 is a deficient number, since it is larger than the sum of its proper divisors (5798269).

166067021 is an frugal number, since it uses more digits than its factorization.

166067021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4815 (or 2422 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 166067021 is about 12886.6993834729. The cubic root of 166067021 is about 549.6604195809.

Multiplying 166067021 by its sum of digits (29), we get a square (4815943609 = 69397²).

166067021 divided by its sum of digits (29) gives a square (5726449 = 2393²).

The spelling of 166067021 in words is "one hundred sixty-six million, sixty-seven thousand, twenty-one".