420520221 has 32 divisors (see below), whose sum is σ = 681744000. Its totient is φ = 254067840.

The previous prime is 420520187. The next prime is 420520237. The reversal of 420520221 is 122025024.

420520221 is a `hidden beast` number, since 420 + 5 + 20 + 221 = 666.

It is not a de Polignac number, because 420520221 - 2⁶ = 420520157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 420520194 and 420520203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420520621) 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 31 ways as a sum of consecutive naturals, for example, 101625 + ... + 105681.

It is an arithmetic number, because the mean of its divisors is an integer number (21304500).

Almost surely, 2^420520221 is an apocalyptic number.

It is an amenable number.

420520221 is a deficient number, since it is larger than the sum of its proper divisors (261223779).

420520221 is a wasteful number, since it uses less digits than its factorization.

420520221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4426 (or 4420 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 420520221 is about 20506.5896969730. The cubic root of 420520221 is about 749.1963070779.

Adding to 420520221 its reverse (122025024), we get a palindrome (542545245).

The spelling of 420520221 in words is "four hundred twenty million, five hundred twenty thousand, two hundred twenty-one".