318421 has 4 divisors (see below), whose sum is σ = 335200. Its totient is φ = 301644.

The previous prime is 318419. The next prime is 318431. The reversal of 318421 is 124813.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 124813 = 13 ⋅9601.

It is not a de Polignac number, because 318421 - 2¹ = 318419 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 16759 = 318421 / (3 + 1 + 8 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (318431) 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, 8361 + ... + 8398.

It is an arithmetic number, because the mean of its divisors is an integer number (83800).

2³¹⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

318421 is a deficient number, since it is larger than the sum of its proper divisors (16779).

318421 is a wasteful number, since it uses less digits than its factorization.

318421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16778.

The product of its digits is 192, while the sum is 19.

The square root of 318421 is about 564.2880470115. The cubic root of 318421 is about 68.2863501480.

The spelling of 318421 in words is "three hundred eighteen thousand, four hundred twenty-one".