840644741 has 6 divisors (see below), whose sum is σ = 846844530. Its totient is φ = 834490016.

The previous prime is 840644737. The next prime is 840644743. The reversal of 840644741 is 147446048.

It can be written as a sum of positive squares in 3 ways, for example, as 37149025 + 803495716 = 6095^2 + 28346^2 .

It is not a de Polignac number, because 840644741 - 2² = 840644737 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 840644695 and 840644704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840644743) 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 5 ways as a sum of consecutive naturals, for example, 3626 + ... + 41163.

It is an arithmetic number, because the mean of its divisors is an integer number (141140755).

Almost surely, 2^840644741 is an apocalyptic number.

It is an amenable number.

840644741 is a deficient number, since it is larger than the sum of its proper divisors (6199789).

840644741 is an equidigital number, since it uses as much as digits as its factorization.

840644741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45063 (or 44926 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 38.

The square root of 840644741 is about 28993.8741978370. The cubic root of 840644741 is about 943.7801383531.

The spelling of 840644741 in words is "eight hundred forty million, six hundred forty-four thousand, seven hundred forty-one".