505621 has 4 divisors (see below), whose sum is σ = 507244. Its totient is φ = 504000.

The previous prime is 505619. The next prime is 505633. The reversal of 505621 is 126505.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126505 = 5 ⋅25301.

It can be written as a sum of positive squares in 2 ways, for example, as 1521 + 504100 = 39^2 + 710^2 .

It is a cyclic number.

It is not a de Polignac number, because 505621 - 2¹ = 505619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505601) 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, 180 + ... + 1021.

It is an arithmetic number, because the mean of its divisors is an integer number (126811).

2⁵⁰⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

505621 is a deficient number, since it is larger than the sum of its proper divisors (1623).

505621 is a wasteful number, since it uses less digits than its factorization.

505621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 505621 is about 711.0703200106. The cubic root of 505621 is about 79.6663709969. Note that the first 3 decimals are identical.

It can be divided in two parts, 50 and 5621, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 505621 in words is "five hundred five thousand, six hundred twenty-one".