42085021 has 16 divisors (see below), whose sum is σ = 48066048. Its totient is φ = 36504000.

The previous prime is 42085007. The next prime is 42085049. The reversal of 42085021 is 12058024.

It is a cyclic number.

It is not a de Polignac number, because 42085021 - 2²³ = 33696413 is a prime.

It is a super-2 number, since 2×42085021² = 3542297985140882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42084983 and 42085001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42085051) 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 15 ways as a sum of consecutive naturals, for example, 20596 + ... + 22546.

It is an arithmetic number, because the mean of its divisors is an integer number (3004128).

Almost surely, 2^42085021 is an apocalyptic number.

It is an amenable number.

42085021 is a deficient number, since it is larger than the sum of its proper divisors (5981027).

42085021 is a wasteful number, since it uses less digits than its factorization.

42085021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2052.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 42085021 is about 6487.2968947012. The cubic root of 42085021 is about 347.8370581927.

It can be divided in two parts, 4208 and 5021, that added together give a palindrome (9229).

The spelling of 42085021 in words is "forty-two million, eighty-five thousand, twenty-one".