166607021 has 16 divisors (see below), whose sum is σ = 203886720. Its totient is φ = 132887040.

The previous prime is 166607017. The next prime is 166607039. The reversal of 166607021 is 120706661.

It is a cyclic number.

It is not a de Polignac number, because 166607021 - 2² = 166607017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166607011) 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, 2726 + ... + 18456.

It is an arithmetic number, because the mean of its divisors is an integer number (12742920).

Almost surely, 2^166607021 is an apocalyptic number.

It is an amenable number.

166607021 is a deficient number, since it is larger than the sum of its proper divisors (37279699).

166607021 is a wasteful number, since it uses less digits than its factorization.

166607021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15844.

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

The square root of 166607021 is about 12907.6342139061. The cubic root of 166607021 is about 550.2555517656.

The spelling of 166607021 in words is "one hundred sixty-six million, six hundred seven thousand, twenty-one".