42000020 has 12 divisors (see below), whose sum is σ = 88200084. Its totient is φ = 16800000.

The previous prime is 42000019. The next prime is 42000029. The reversal of 42000020 is 2000024.

It can be written as a sum of positive squares in 2 ways, for example, as 33131536 + 8868484 = 5756^2 + 2978^2 .

It is a junction number, because it is equal to n+sod(n) for n = 41999971 and 42000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42000029) 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, 1049981 + ... + 1050020.

It is an arithmetic number, because the mean of its divisors is an integer number (7350007).

Almost surely, 2^42000020 is an apocalyptic number.

It is an amenable number.

42000020 is an abundant number, since it is smaller than the sum of its proper divisors (46200064).

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

42000020 is a wasteful number, since it uses less digits than its factorization.

42000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2100010 (or 2100008 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 8.

The square root of 42000020 is about 6480.7422414412. The cubic root of 42000020 is about 347.6027196637.

Adding to 42000020 its reverse (2000024), we get a palindrome (44000044).

The spelling of 42000020 in words is "forty-two million, twenty", and thus it is an aban number and an uban number.