420024021 has 4 divisors (see below), whose sum is σ = 560032032. Its totient is φ = 280016012.

The previous prime is 420023987. The next prime is 420024029. The reversal of 420024021 is 120420024.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 420024021 - 2⁷ = 420023893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420024029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70004001 + ... + 70004006.

It is an arithmetic number, because the mean of its divisors is an integer number (140008008).

Almost surely, 2^420024021 is an apocalyptic number.

It is an amenable number.

420024021 is a deficient number, since it is larger than the sum of its proper divisors (140008011).

420024021 is a wasteful number, since it uses less digits than its factorization.

420024021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140008010.

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 420024021 is about 20494.4875759312. The cubic root of 420024021 is about 748.9015154500.

Adding to 420024021 its reverse (120420024), we get a palindrome (540444045).

The spelling of 420024021 in words is "four hundred twenty million, twenty-four thousand, twenty-one".