401891 has 4 divisors (see below), whose sum is σ = 459312. Its totient is φ = 344472.

The previous prime is 401887. The next prime is 401903. The reversal of 401891 is 198104.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 401891 - 2² = 401887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (401861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28700 + ... + 28713.

It is an arithmetic number, because the mean of its divisors is an integer number (114828).

2⁴⁰¹⁸⁹¹ is an apocalyptic number.

401891 is a deficient number, since it is larger than the sum of its proper divisors (57421).

401891 is an equidigital number, since it uses as much as digits as its factorization.

401891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57420.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 401891 is about 633.9487360978. The cubic root of 401891 is about 73.7965558771.

Adding to 401891 its reverse (198104), we get a palindrome (599995).

The spelling of 401891 in words is "four hundred one thousand, eight hundred ninety-one".