840404 has 6 divisors (see below), whose sum is σ = 1470714. Its totient is φ = 420200.

The previous prime is 840353. The next prime is 840439. The reversal of 840404 is 404048.

840404 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 559504 + 280900 = 748^2 + 530^2 .

840404 is a modest number, since divided by 404 gives 84 as remainder.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840404.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105047 + ... + 105054.

It is an arithmetic number, because the mean of its divisors is an integer number (245119).

2⁸⁴⁰⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

840404 is a deficient number, since it is larger than the sum of its proper divisors (630310).

840404 is a wasteful number, since it uses less digits than its factorization.

840404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210105 (or 210103 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 840404 is about 916.7355125662. The cubic root of 840404 is about 94.3690037563.

The spelling of 840404 in words is "eight hundred forty thousand, four hundred four".