812621 has 4 divisors (see below), whose sum is σ = 815100. Its totient is φ = 810144.

The previous prime is 812599. The next prime is 812627. The reversal of 812621 is 126218.

812621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 469225 + 343396 = 685^2 + 586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-812621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 812593 and 812602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812627) 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, 656 + ... + 1433.

It is an arithmetic number, because the mean of its divisors is an integer number (203775).

2⁸¹²⁶²¹ is an apocalyptic number.

It is an amenable number.

812621 is a deficient number, since it is larger than the sum of its proper divisors (2479).

812621 is a wasteful number, since it uses less digits than its factorization.

812621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2478.

The product of its digits is 192, while the sum is 20.

The square root of 812621 is about 901.4549350910. The cubic root of 812621 is about 93.3174108326.

Adding to 812621 its reverse (126218), we get a palindrome (938839).

The spelling of 812621 in words is "eight hundred twelve thousand, six hundred twenty-one".