42021439 has 4 divisors (see below), whose sum is σ = 42493680. Its totient is φ = 41549200.

The previous prime is 42021401. The next prime is 42021509. The reversal of 42021439 is 93412024.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42021439 - 2¹⁹ = 41497151 is a prime.

It is a super-3 number, since 3×42021439³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42021139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235987 + ... + 236164.

It is an arithmetic number, because the mean of its divisors is an integer number (10623420).

Almost surely, 2^42021439 is an apocalyptic number.

42021439 is a deficient number, since it is larger than the sum of its proper divisors (472241).

42021439 is an equidigital number, since it uses as much as digits as its factorization.

42021439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472240.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 42021439 is about 6482.3945421426. The cubic root of 42021439 is about 347.6617992972.

The spelling of 42021439 in words is "forty-two million, twenty-one thousand, four hundred thirty-nine".