420020521 has 4 divisors (see below), whose sum is σ = 426289552. Its totient is φ = 413751492.

The previous prime is 420020509. The next prime is 420020527. The reversal of 420020521 is 125020024.

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 420020521 - 2⁹ = 420020009 is a prime.

It is a super-2 number, since 2×420020521² = 352834476122222882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 420020495 and 420020504.

It is not an unprimeable number, because it can be changed into a prime (420020527) 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, 3134415 + ... + 3134548.

It is an arithmetic number, because the mean of its divisors is an integer number (106572388).

Almost surely, 2^420020521 is an apocalyptic number.

It is an amenable number.

420020521 is a deficient number, since it is larger than the sum of its proper divisors (6269031).

420020521 is an equidigital number, since it uses as much as digits as its factorization.

420020521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6269030.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 420020521 is about 20494.4021869388. The cubic root of 420020521 is about 748.8994352812.

Adding to 420020521 its reverse (125020024), we get a palindrome (545040545).

The spelling of 420020521 in words is "four hundred twenty million, twenty thousand, five hundred twenty-one".