820042000 has 80 divisors (see below), whose sum is σ = 2069188992. Its totient is φ = 313737600.

The previous prime is 820041967. The next prime is 820042007. The reversal of 820042000 is 240028.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (820042007) 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 15 ways as a sum of consecutive naturals, for example, 37087 + ... + 54913.

Almost surely, 2^820042000 is an apocalyptic number.

820042000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820042000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1034594496).

820042000 is an abundant number, since it is smaller than the sum of its proper divisors (1249146992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820042000 is a wasteful number, since it uses less digits than its factorization.

820042000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17873 (or 17857 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 820042000 is about 28636.3754689730. The cubic root of 820042000 is about 936.0061423611.

Adding to 820042000 its reverse (240028), we get a palindrome (820282028).

The spelling of 820042000 in words is "eight hundred twenty million, forty-two thousand".