805763821 has 4 divisors (see below), whose sum is σ = 813294432. Its totient is φ = 798233212.

The previous prime is 805763813. The next prime is 805763831. The reversal of 805763821 is 128367508.

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 805763821 - 2³ = 805763813 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 (805763831) 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, 3765145 + ... + 3765358.

It is an arithmetic number, because the mean of its divisors is an integer number (203323608).

Almost surely, 2^805763821 is an apocalyptic number.

It is an amenable number.

805763821 is a deficient number, since it is larger than the sum of its proper divisors (7530611).

805763821 is a wasteful number, since it uses less digits than its factorization.

805763821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7530610.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 805763821 is about 28385.9793031701. The cubic root of 805763821 is about 930.5418744437.

The spelling of 805763821 in words is "eight hundred five million, seven hundred sixty-three thousand, eight hundred twenty-one".