42004021 has 8 divisors (see below), whose sum is σ = 42517440. Its totient is φ = 41493312.

The previous prime is 42004013. The next prime is 42004069. The reversal of 42004021 is 12040024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42004021 - 2³ = 42004013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42003992 and 42004010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42004321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56470 + ... + 57208.

It is an arithmetic number, because the mean of its divisors is an integer number (5314680).

Almost surely, 2^42004021 is an apocalyptic number.

It is an amenable number.

42004021 is a deficient number, since it is larger than the sum of its proper divisors (513419).

42004021 is a wasteful number, since it uses less digits than its factorization.

42004021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 42004021 is about 6481.0509178682. The cubic root of 42004021 is about 347.6137570737.

Adding to 42004021 its reverse (12040024), we get a palindrome (54044045).

The spelling of 42004021 in words is "forty-two million, four thousand, twenty-one".