166553021 has 8 divisors (see below), whose sum is σ = 171257184. Its totient is φ = 161859600.

The previous prime is 166552973. The next prime is 166553027. The reversal of 166553021 is 120355661.

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

It is a cyclic number.

It is not a de Polignac number, because 166553021 - 2¹⁰ = 166551997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166553027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36746 + ... + 41028.

It is an arithmetic number, because the mean of its divisors is an integer number (21407148).

Almost surely, 2^166553021 is an apocalyptic number.

It is an amenable number.

166553021 is a deficient number, since it is larger than the sum of its proper divisors (4704163).

166553021 is a wasteful number, since it uses less digits than its factorization.

166553021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5371.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 166553021 is about 12905.5422590451. The cubic root of 166553021 is about 550.1960964668.

The spelling of 166553021 in words is "one hundred sixty-six million, five hundred fifty-three thousand, twenty-one".