42091020 has 72 divisors (see below), whose sum is σ = 128432304. Its totient is φ = 11157888.

The previous prime is 42091019. The next prime is 42091033. The reversal of 42091020 is 2019024.

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

It is a junction number, because it is equal to n+sod(n) for n = 42090984 and 42091002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34867 + ... + 36053.

It is an arithmetic number, because the mean of its divisors is an integer number (1783782).

Almost surely, 2^42091020 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 42091020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64216152).

42091020 is an abundant number, since it is smaller than the sum of its proper divisors (86341284).

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

42091020 is a wasteful number, since it uses less digits than its factorization.

42091020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399 (or 1394 counting only the distinct ones).

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

The square root of 42091020 is about 6487.7592433752. The cubic root of 42091020 is about 347.8535848596.

The spelling of 42091020 in words is "forty-two million, ninety-one thousand, twenty".