840641 has 4 divisors (see below), whose sum is σ = 854484. Its totient is φ = 826800.

The previous prime is 840611. The next prime is 840643. The reversal of 840641 is 146048.

It is a happy number.

840641 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.

It can be written as a sum of positive squares in 2 ways, for example, as 207025 + 633616 = 455^2 + 796^2 .

It is a cyclic number.

It is not a de Polignac number, because 840641 - 2¹⁰ = 839617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840643) 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, 6830 + ... + 6951.

It is an arithmetic number, because the mean of its divisors is an integer number (213621).

2⁸⁴⁰⁶⁴¹ is an apocalyptic number.

It is an amenable number.

840641 is a deficient number, since it is larger than the sum of its proper divisors (13843).

840641 is a wasteful number, since it uses less digits than its factorization.

840641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13842.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 840641 is about 916.8647664732. The cubic root of 840641 is about 94.3778738361.

Adding to 840641 its reverse (146048), we get a palindrome (986689).

The spelling of 840641 in words is "eight hundred forty thousand, six hundred forty-one".