403891 has 4 divisors (see below), whose sum is σ = 413784. Its totient is φ = 394000.

The previous prime is 403889. The next prime is 403901. The reversal of 403891 is 198304.

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 403891 - 2¹ = 403889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (403831) 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, 4885 + ... + 4966.

It is an arithmetic number, because the mean of its divisors is an integer number (103446).

2⁴⁰³⁸⁹¹ is an apocalyptic number.

403891 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

403891 is a deficient number, since it is larger than the sum of its proper divisors (9893).

403891 is an equidigital number, since it uses as much as digits as its factorization.

403891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9892.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 403891 is about 635.5241930879. The cubic root of 403891 is about 73.9187689111.

The spelling of 403891 in words is "four hundred three thousand, eight hundred ninety-one".