840029 has 4 divisors (see below), whose sum is σ = 876576. Its totient is φ = 803484.

The previous prime is 840023. The next prime is 840053. The reversal of 840029 is 920048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-840029 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 36523 = 840029 / (8 + 4 + 0 + 0 + 2 + 9).

It is a junction number, because it is equal to n+sod(n) for n = 839986 and 840013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18239 + ... + 18284.

It is an arithmetic number, because the mean of its divisors is an integer number (219144).

2⁸⁴⁰⁰²⁹ is an apocalyptic number.

It is an amenable number.

840029 is a deficient number, since it is larger than the sum of its proper divisors (36547).

840029 is a wasteful number, since it uses less digits than its factorization.

840029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36546.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 840029 is about 916.5309596517. The cubic root of 840029 is about 94.3549654123.

The spelling of 840029 in words is "eight hundred forty thousand, twenty-nine".