864621 has 16 divisors (see below), whose sum is σ = 1323520. Its totient is φ = 557280.

The previous prime is 864613. The next prime is 864623. The reversal of 864621 is 126468.

It is not a de Polignac number, because 864621 - 2³ = 864613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 321 + ... + 1353.

It is an arithmetic number, because the mean of its divisors is an integer number (82720).

2⁸⁶⁴⁶²¹ is an apocalyptic number.

It is an amenable number.

864621 is a deficient number, since it is larger than the sum of its proper divisors (458899).

864621 is a wasteful number, since it uses less digits than its factorization.

864621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073 (or 1067 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 864621 is about 929.8499879013. The cubic root of 864621 is about 95.2668765434.

864621 divided by its sum of digits (27) gives a palindrome (32023).

It can be divided in two parts, 864 and 621, that added together give a triangular number (1485 = T₅₄).

The spelling of 864621 in words is "eight hundred sixty-four thousand, six hundred twenty-one".