42066820 has 72 divisors (see below), whose sum is σ = 95259528. Its totient is φ = 15590400.

The previous prime is 42066811. The next prime is 42066841. The reversal of 42066820 is 2866024.

It can be written as a sum of positive squares in 12 ways, for example, as 30669444 + 11397376 = 5538^2 + 3376^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 689590 + ... + 689650.

It is an arithmetic number, because the mean of its divisors is an integer number (1323049).

Almost surely, 2^42066820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42066820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47629764).

42066820 is an abundant number, since it is smaller than the sum of its proper divisors (53192708).

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

42066820 is a wasteful number, since it uses less digits than its factorization.

42066820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 42066820 is about 6485.8939245103. The cubic root of 42066820 is about 347.7869065786.

It can be divided in two parts, 4206 and 6820, that added together give a triangular number (11026 = T₁₄₈).

The spelling of 42066820 in words is "forty-two million, sixty-six thousand, eight hundred twenty".