420055021 has 4 divisors (see below), whose sum is σ = 442163200. Its totient is φ = 397946844.

The previous prime is 420055019. The next prime is 420055033. The reversal of 420055021 is 120550024.

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 420055021 - 2¹ = 420055019 is a prime.

It is a super-3 number, since 3×420055021³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 22108159 = 420055021 / (4 + 2 + 0 + 0 + 5 + 5 + 0 + 2 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 420055021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420055001) 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, 11054061 + ... + 11054098.

It is an arithmetic number, because the mean of its divisors is an integer number (110540800).

Almost surely, 2^420055021 is an apocalyptic number.

It is an amenable number.

420055021 is a deficient number, since it is larger than the sum of its proper divisors (22108179).

420055021 is a wasteful number, since it uses less digits than its factorization.

420055021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22108178.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 420055021 is about 20495.2438629063. The cubic root of 420055021 is about 748.9199392977.

The spelling of 420055021 in words is "four hundred twenty million, fifty-five thousand, twenty-one".