421042021 has 4 divisors (see below), whose sum is σ = 422215200. Its totient is φ = 419868844.

The previous prime is 421041977. The next prime is 421042049. The reversal of 421042021 is 120240124.

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 421042021 - 2¹¹ = 421039973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421041986 and 421042004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421042051) 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, 586051 + ... + 586768.

It is an arithmetic number, because the mean of its divisors is an integer number (105553800).

Almost surely, 2^421042021 is an apocalyptic number.

It is an amenable number.

421042021 is a deficient number, since it is larger than the sum of its proper divisors (1173179).

421042021 is a wasteful number, since it uses less digits than its factorization.

421042021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1173178.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 421042021 is about 20519.3084922470. The cubic root of 421042021 is about 749.5060575807.

Adding to 421042021 its reverse (120240124), we get a palindrome (541282145).

The spelling of 421042021 in words is "four hundred twenty-one million, forty-two thousand, twenty-one".