406191 has 8 divisors (see below), whose sum is σ = 549504. Its totient is φ = 266840.

The previous prime is 406183. The next prime is 406207. The reversal of 406191 is 191604.

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 406191 - 2³ = 406183 is a prime.

It is a super-2 number, since 2×406191² = 329982256962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 741 + ... + 1166.

It is an arithmetic number, because the mean of its divisors is an integer number (68688).

2⁴⁰⁶¹⁹¹ is an apocalyptic number.

406191 is a deficient number, since it is larger than the sum of its proper divisors (143313).

406191 is a wasteful number, since it uses less digits than its factorization.

406191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1981.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 406191 is about 637.3311541106. The cubic root of 406191 is about 74.0588161567.

Adding to 406191 its reverse (191604), we get a palindrome (597795).

The spelling of 406191 in words is "four hundred six thousand, one hundred ninety-one".