820624 has 40 divisors (see below), whose sum is σ = 1928448. Its totient is φ = 330240.

The previous prime is 820619. The next prime is 820627. The reversal of 820624 is 426028.

It is an Ulam number.

It is a d-powerful number, because it can be written as 8 + 2³ + 6⁷ + 0 + 2¹⁹ + 4⁷ .

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 820595 and 820604.

It is not an unprimeable number, because it can be changed into a prime (820627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1689 + ... + 2119.

2⁸²⁰⁶²⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (964224).

820624 is an abundant number, since it is smaller than the sum of its proper divisors (1107824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820624 is a wasteful number, since it uses less digits than its factorization.

820624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463 (or 457 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 820624 is about 905.8829946522. The cubic root of 820624 is about 93.6227524010.

It can be divided in two parts, 820 and 624, that added together give a square (1444 = 38²).

The spelling of 820624 in words is "eight hundred twenty thousand, six hundred twenty-four".