420581 has 4 divisors (see below), whose sum is σ = 480672. Its totient is φ = 360492.

The previous prime is 420571. The next prime is 420593. The reversal of 420581 is 185024.

420581 = T₁₂₀ + T₁₂₁ + ... + T₁₆₁.

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 420581 - 2¹⁰ = 419557 is a prime.

It is a super-2 number, since 2×420581² = 353776755122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 420581.

It is not an unprimeable number, because it can be changed into a prime (420521) 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 3 ways as a sum of consecutive naturals, for example, 30035 + ... + 30048.

It is an arithmetic number, because the mean of its divisors is an integer number (120168).

2⁴²⁰⁵⁸¹ is an apocalyptic number.

It is an amenable number.

420581 is a deficient number, since it is larger than the sum of its proper divisors (60091).

420581 is an equidigital number, since it uses as much as digits as its factorization.

420581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60090.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 420581 is about 648.5221661593. The cubic root of 420581 is about 74.9232399840.

It can be divided in two parts, 420 and 581, that added together give a palindrome (1001).

The spelling of 420581 in words is "four hundred twenty thousand, five hundred eighty-one".