42021047 has 4 divisors (see below), whose sum is σ = 42036456. Its totient is φ = 42005640.

The previous prime is 42021043. The next prime is 42021071. The reversal of 42021047 is 74012024.

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 42021047 - 2² = 42021043 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42021043) 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 3 ways as a sum of consecutive naturals, for example, 2393 + ... + 9474.

It is an arithmetic number, because the mean of its divisors is an integer number (10509114).

Almost surely, 2^42021047 is an apocalyptic number.

42021047 is a deficient number, since it is larger than the sum of its proper divisors (15409).

42021047 is a wasteful number, since it uses less digits than its factorization.

42021047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15408.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 42021047 is about 6482.3643063314. The cubic root of 42021047 is about 347.6607182312.

The spelling of 42021047 in words is "forty-two million, twenty-one thousand, forty-seven".