840286921 has 8 divisors (see below), whose sum is σ = 843864320. Its totient is φ = 836716608.

The previous prime is 840286901. The next prime is 840286933. The reversal of 840286921 is 129682048.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 840286921 - 2²³ = 831898313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840286901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 446260 + ... + 448138.

It is an arithmetic number, because the mean of its divisors is an integer number (105483040).

Almost surely, 2^840286921 is an apocalyptic number.

It is an amenable number.

840286921 is a deficient number, since it is larger than the sum of its proper divisors (3577399).

840286921 is a wasteful number, since it uses less digits than its factorization.

840286921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3543.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 840286921 is about 28987.7029272759. The cubic root of 840286921 is about 943.6462128399.

The spelling of 840286921 in words is "eight hundred forty million, two hundred eighty-six thousand, nine hundred twenty-one".