864421 has 4 divisors (see below), whose sum is σ = 866752. Its totient is φ = 862092.

The previous prime is 864419. The next prime is 864427. The reversal of 864421 is 124468.

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 a cyclic number.

It is not a de Polignac number, because 864421 - 2¹ = 864419 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

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 (864427) 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, 471 + ... + 1396.

It is an arithmetic number, because the mean of its divisors is an integer number (216688).

2⁸⁶⁴⁴²¹ is an apocalyptic number.

It is an amenable number.

864421 is a deficient number, since it is larger than the sum of its proper divisors (2331).

864421 is a wasteful number, since it uses less digits than its factorization.

864421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2330.

The product of its digits is 1536, while the sum is 25.

The square root of 864421 is about 929.7424374524. The cubic root of 864421 is about 95.2595304173.

Adding to 864421 its reverse (124468), we get a palindrome (988889).

The spelling of 864421 in words is "eight hundred sixty-four thousand, four hundred twenty-one".