42009820 has 24 divisors (see below), whose sum is σ = 88550784. Its totient is φ = 16741056.

The previous prime is 42009809. The next prime is 42009823. The reversal of 42009820 is 2890024.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42009823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1749 + ... + 9331.

It is an arithmetic number, because the mean of its divisors is an integer number (3689616).

Almost surely, 2^42009820 is an apocalyptic number.

It is an amenable number.

42009820 is an abundant number, since it is smaller than the sum of its proper divisors (46540964).

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

42009820 is a wasteful number, since it uses less digits than its factorization.

42009820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7869 (or 7867 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 42009820 is about 6481.4982835761. The cubic root of 42009820 is about 347.6297533154.

Adding to 42009820 its reverse (2890024), we get a palindrome (44899844).

The spelling of 42009820 in words is "forty-two million, nine thousand, eight hundred twenty".