42008021 has 8 divisors (see below), whose sum is σ = 46281888. Its totient is φ = 37810000.

The previous prime is 42008009. The next prime is 42008023. The reversal of 42008021 is 12080024.

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 42008021 - 2⁶ = 42007957 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 (42008023) 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, 17795 + ... + 20016.

It is an arithmetic number, because the mean of its divisors is an integer number (5785236).

Almost surely, 2^42008021 is an apocalyptic number.

It is an amenable number.

42008021 is a deficient number, since it is larger than the sum of its proper divisors (4273867).

42008021 is a wasteful number, since it uses less digits than its factorization.

42008021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37923.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 42008021 is about 6481.3595024501. The cubic root of 42008021 is about 347.6247910244.

Adding to 42008021 its reverse (12080024), we get a palindrome (54088045).

It can be divided in two parts, 4200 and 8021, that added together give a palindrome (12221).

The spelling of 42008021 in words is "forty-two million, eight thousand, twenty-one".