866304821 has 4 divisors (see below), whose sum is σ = 903970272. Its totient is φ = 828639372.

The previous prime is 866304793. The next prime is 866304823. The reversal of 866304821 is 128403668.

It is a happy number.

866304821 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, 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 866304821 - 2¹⁰ = 866303797 is a prime.

It is a super-3 number, since 3×866304821³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866304823) 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, 18832691 + ... + 18832736.

It is an arithmetic number, because the mean of its divisors is an integer number (225992568).

Almost surely, 2^866304821 is an apocalyptic number.

It is an amenable number.

866304821 is a deficient number, since it is larger than the sum of its proper divisors (37665451).

866304821 is a wasteful number, since it uses less digits than its factorization.

866304821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37665450.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 866304821 is about 29433.0566030781. The cubic root of 866304821 is about 953.2867947870.

The spelling of 866304821 in words is "eight hundred sixty-six million, three hundred four thousand, eight hundred twenty-one".