171606421 has 32 divisors (see below), whose sum is σ = 211673088. Its totient is φ = 136019520.

The previous prime is 171606377. The next prime is 171606431. The reversal of 171606421 is 124606171.

It is not a de Polignac number, because 171606421 - 2¹⁷ = 171475349 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 171606421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171606431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 494370 + ... + 494716.

It is an arithmetic number, because the mean of its divisors is an integer number (6614784).

Almost surely, 2^171606421 is an apocalyptic number.

It is an amenable number.

171606421 is a deficient number, since it is larger than the sum of its proper divisors (40066667).

171606421 is a wasteful number, since it uses less digits than its factorization.

171606421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 171606421 is about 13099.8633962343. The cubic root of 171606421 is about 555.7052647037.

The spelling of 171606421 in words is "one hundred seventy-one million, six hundred six thousand, four hundred twenty-one".