420205521 has 8 divisors (see below), whose sum is σ = 572194944. Its totient is φ = 274176560.

The previous prime is 420205519. The next prime is 420205523. The reversal of 420205521 is 125502024.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (420205519) and next prime (420205523).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 420205521 - 2¹ = 420205519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (420205523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1489950 + ... + 1490231.

It is an arithmetic number, because the mean of its divisors is an integer number (71524368).

Almost surely, 2^420205521 is an apocalyptic number.

It is an amenable number.

420205521 is a deficient number, since it is larger than the sum of its proper divisors (151989423).

420205521 is a wasteful number, since it uses less digits than its factorization.

420205521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980231.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 420205521 is about 20498.9151176349. The cubic root of 420205521 is about 749.0093712267.

Adding to 420205521 its reverse (125502024), we get a palindrome (545707545).

The spelling of 420205521 in words is "four hundred twenty million, two hundred five thousand, five hundred twenty-one".