42021090 has 48 divisors (see below), whose sum is σ = 110073600. Its totient is φ = 11121696.

The previous prime is 42021073. The next prime is 42021121. The reversal of 42021090 is 9012024.

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

It is a Curzon 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, 10831 + ... + 14189.

It is an arithmetic number, because the mean of its divisors is an integer number (2293200).

Almost surely, 2^42021090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42021090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55036800).

42021090 is an abundant number, since it is smaller than the sum of its proper divisors (68052510).

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

42021090 is a wasteful number, since it uses less digits than its factorization.

42021090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3511 (or 3508 counting only the distinct ones).

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

The square root of 42021090 is about 6482.3676230217. The cubic root of 42021090 is about 347.6608368178.

The spelling of 42021090 in words is "forty-two million, twenty-one thousand, ninety".