840219161 has 4 divisors (see below), whose sum is σ = 840391524. Its totient is φ = 840046800.

The previous prime is 840219157. The next prime is 840219167. The reversal of 840219161 is 161912048.

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

It can be written as a sum of positive squares in 2 ways, for example, as 507375625 + 332843536 = 22525^2 + 18244^2 .

It is a cyclic number.

It is not a de Polignac number, because 840219161 - 2² = 840219157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840219167) 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 3 ways as a sum of consecutive naturals, for example, 78650 + ... + 88691.

It is an arithmetic number, because the mean of its divisors is an integer number (210097881).

Almost surely, 2^840219161 is an apocalyptic number.

It is an amenable number.

840219161 is a deficient number, since it is larger than the sum of its proper divisors (172363).

840219161 is a wasteful number, since it uses less digits than its factorization.

840219161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172362.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 840219161 is about 28986.5341322484. The cubic root of 840219161 is about 943.6208472239.

The spelling of 840219161 in words is "eight hundred forty million, two hundred nineteen thousand, one hundred sixty-one".