806551 has 4 divisors (see below), whose sum is σ = 825352. Its totient is φ = 787752.

The previous prime is 806549. The next prime is 806579. The reversal of 806551 is 155608.

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

It is a cyclic number.

It is not a de Polignac number, because 806551 - 2¹ = 806549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (806521) 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, 9336 + ... + 9421.

It is an arithmetic number, because the mean of its divisors is an integer number (206338).

2⁸⁰⁶⁵⁵¹ is an apocalyptic number.

806551 is a deficient number, since it is larger than the sum of its proper divisors (18801).

806551 is a wasteful number, since it uses less digits than its factorization.

806551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18800.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 806551 is about 898.0818448226. The cubic root of 806551 is about 93.0844802174.

It can be divided in two parts, 80655 and 1, that added together give a square (80656 = 284²).

The spelling of 806551 in words is "eight hundred six thousand, five hundred fifty-one".