840193861 has 8 divisors (see below), whose sum is σ = 905716224. Its totient is φ = 774798960.

The previous prime is 840193843. The next prime is 840193877. The reversal of 840193861 is 168391048.

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

It is not a de Polignac number, because 840193861 - 2¹⁵ = 840161093 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 (840193561) 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, 17941 + ... + 44746.

It is an arithmetic number, because the mean of its divisors is an integer number (113214528).

Almost surely, 2^840193861 is an apocalyptic number.

It is an amenable number.

840193861 is a deficient number, since it is larger than the sum of its proper divisors (65522363).

840193861 is a wasteful number, since it uses less digits than its factorization.

840193861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63731.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 840193861 is about 28986.0977194240. The cubic root of 840193861 is about 943.6113759462.

The spelling of 840193861 in words is "eight hundred forty million, one hundred ninety-three thousand, eight hundred sixty-one".