42120900 has 108 divisors (see below), whose sum is σ = 139842612. Its totient is φ = 10567680.

The previous prime is 42120893. The next prime is 42120901. The reversal of 42120900 is 902124.

It can be written as a sum of positive squares in 6 ways, for example, as 2883204 + 39237696 = 1698^2 + 6264^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (42120901) 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 35 ways as a sum of consecutive naturals, for example, 13924 + ... + 16676.

It is an arithmetic number, because the mean of its divisors is an integer number (1294839).

Almost surely, 2^42120900 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 42120900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69921306).

42120900 is an abundant number, since it is smaller than the sum of its proper divisors (97721712).

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

42120900 is a wasteful number, since it uses less digits than its factorization.

42120900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2790 (or 2780 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 42120900 is about 6490.0616329893. The cubic root of 42120900 is about 347.9358779994.

It can be divided in two parts, 421 and 20900, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 42120900 in words is "forty-two million, one hundred twenty thousand, nine hundred".