812521 has 4 divisors (see below), whose sum is σ = 847872. Its totient is φ = 777172.

The previous prime is 812519. The next prime is 812527. The reversal of 812521 is 125218.

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 812521 - 2¹ = 812519 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (812527) 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 3 ways as a sum of consecutive naturals, for example, 17641 + ... + 17686.

It is an arithmetic number, because the mean of its divisors is an integer number (211968).

2⁸¹²⁵²¹ is an apocalyptic number.

It is an amenable number.

812521 is a deficient number, since it is larger than the sum of its proper divisors (35351).

812521 is a wasteful number, since it uses less digits than its factorization.

812521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35350.

The product of its digits is 160, while the sum is 19.

The square root of 812521 is about 901.3994674949. The cubic root of 812521 is about 93.3135828390.

Adding to 812521 its reverse (125218), we get a palindrome (937739).

The spelling of 812521 in words is "eight hundred twelve thousand, five hundred twenty-one".