86421 has 4 divisors (see below), whose sum is σ = 115232. Its totient is φ = 57612.

The previous prime is 86413. The next prime is 86423. The reversal of 86421 is 12468.

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.

It is not a de Polignac number, because 86421 - 2³ = 86413 is a prime.

It is a D-number.

It is a Duffinian number.

86421 is a lucky number.

It is a plaindrome in base 14.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86423) 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, 14401 + ... + 14406.

It is an arithmetic number, because the mean of its divisors is an integer number (28808).

2⁸⁶⁴²¹ is an apocalyptic number.

It is an amenable number.

86421 is a deficient number, since it is larger than the sum of its proper divisors (28811).

86421 is a wasteful number, since it uses less digits than its factorization.

86421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28810.

The product of its digits is 384, while the sum is 21.

The square root of 86421 is about 293.9744886891. The cubic root of 86421 is about 44.2119593908.

Adding to 86421 its reverse (12468), we get a palindrome (98889).

The spelling of 86421 in words is "eighty-six thousand, four hundred twenty-one".