42020421 has 4 divisors (see below), whose sum is σ = 56027232. Its totient is φ = 28013612.

The previous prime is 42020393. The next prime is 42020437. The reversal of 42020421 is 12402024.

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 42020421 - 2⁶ = 42020357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42020421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42020441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7003401 + ... + 7003406.

It is an arithmetic number, because the mean of its divisors is an integer number (14006808).

Almost surely, 2^42020421 is an apocalyptic number.

It is an amenable number.

42020421 is a deficient number, since it is larger than the sum of its proper divisors (14006811).

42020421 is a wasteful number, since it uses less digits than its factorization.

42020421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14006810.

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

The square root of 42020421 is about 6482.3160212998. The cubic root of 42020421 is about 347.6589918210.

Adding to 42020421 its reverse (12402024), we get a palindrome (54422445).

The spelling of 42020421 in words is "forty-two million, twenty thousand, four hundred twenty-one".