166006421 has 8 divisors (see below), whose sum is σ = 189957120. Its totient is φ = 142114608.

The previous prime is 166006409. The next prime is 166006427. The reversal of 166006421 is 124600661.

It is a happy number.

166006421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 166006421 - 2¹⁰ = 166005397 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 (166006427) 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, 8501 + ... + 20106.

It is an arithmetic number, because the mean of its divisors is an integer number (23744640).

Almost surely, 2^166006421 is an apocalyptic number.

It is an amenable number.

166006421 is a deficient number, since it is larger than the sum of its proper divisors (23950699).

166006421 is an equidigital number, since it uses as much as digits as its factorization.

166006421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29443.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 166006421 is about 12884.3479074418. The cubic root of 166006421 is about 549.5935520521.

The spelling of 166006421 in words is "one hundred sixty-six million, six thousand, four hundred twenty-one".