42408021 has 8 divisors (see below), whose sum is σ = 59002560. Its totient is φ = 27042752.

The previous prime is 42408017. The next prime is 42408029. The reversal of 42408021 is 12080424.

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 42408021 - 2² = 42408017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42408029) 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 7 ways as a sum of consecutive naturals, for example, 307236 + ... + 307373.

It is an arithmetic number, because the mean of its divisors is an integer number (7375320).

Almost surely, 2^42408021 is an apocalyptic number.

It is an amenable number.

42408021 is a deficient number, since it is larger than the sum of its proper divisors (16594539).

42408021 is a wasteful number, since it uses less digits than its factorization.

42408021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614635.

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 42408021 is about 6512.1441169556. The cubic root of 42408021 is about 348.7246674216.

Adding to 42408021 its reverse (12080424), we get a palindrome (54488445).

The spelling of 42408021 in words is "forty-two million, four hundred eight thousand, twenty-one".